# The State of Email Marketing: September edition

Canonical: https://brew.new/blog/state-of-email-september-2026
Author: Thomas Park
Published: 2026-09-30
Updated: 2026-09-30

The State of Email is our monthly report on what changed for people who send marketing and lifecycle email: the mailbox providers, the platforms, the numbers, the rules and the season ahead. Every claim links to its source, and when a vendor is reporting on its own customers, we say so.

This first edition covers August and September 2026. The short version: inboxes got more AI readers, email platforms let outside agents do more, Gmail's rules held while one of its best-loved dashboards went away, and every holiday forecast expects online spending to beat retail overall. Short on time? The October checklist near the end is the part to act on.

![A timeline of the email events covered in this edition, from Loops' Claude connector on August 12 to Validity's holiday survey on September 30.](/images/blog/state-of-email-september-2026-timeline.png)

*Sixteen dated events behind this edition. Each one is linked below.*

## Key takeaways

- Apple shipped iOS 27 with Siri AI on September 14, and Gmail's AI Overviews in search went global on September 15. More of your email will be found and summarized by an assistant before anyone reads it.
- Gmail's sender rules did not change, but Postmaster Tools v1 is being retired and v2 has no domain or IP reputation dashboard. Watch spam rate and your own engagement data instead.
- Klaviyo, HubSpot, Salesforce, Braze, Customer.io, Brevo, beehiiv, Loops and Brew all shipped new or expanded agent access between August 12 and September 29.
- Published open-rate benchmarks run from 11% to 43% because each vendor counts differently, so compare against your own history. Brew customers averaged a 35.6% open rate and a 42% click-to-open rate in August and September, with machine opens and bot clicks filtered out.
- Adobe expects $275.1 billion in US online holiday sales for November and December, plus $95.8 billion in October. October is part of the season now.

## The inbox has more AI readers

### Apple: iOS 27 and Siri AI

Apple released iOS 27, iPadOS 27 and macOS 27 on [September 14](https://www.apple.com/newsroom/2026/09/major-updates-for-apples-software-platforms-are-now-available/). Siri AI, the headline feature, "can understand personal context across messages, emails, photos, and more." It launched as an English beta, with French, Japanese, Korean, Portuguese and Spanish due in October, and it is not initially available in the EU on iOS, iPadOS and watchOS.

Mail search changed too: "a completely new ranking system in Mail surfaces even more relevant results in Top Hits," and Mail now searches "based on what you mean, not just the words you type," as [9to5Mac noticed](https://9to5mac.com/2026/09/23/ios-27-gives-apple-mail-my-most-wished-for-feature-upgrade/).

Validity's [read of the release](https://www.validity.com/blog/email-radar-what-apples-september-2026-release-means-for-email/) is blunt: "marketers should expect traditional engagement metrics (opens, clicks, etc.) to underrepresent actual message usefulness as Apple's role as an intermediary between brands and recipients deepens." Apple said nothing new about Mail Privacy Protection, so treat Apple Mail opens as just as unreliable as before.

### Google: AI Overviews and Gmail Live

On [September 15](https://workspaceupdates.googleblog.com/2026/09/gmail-searchs-ai-overviews-now-available-globally.html), Google took AI Overviews in Gmail search worldwide for paid plans with Gmail set to English. It answers questions typed into the search bar with "concise summaries and answers without digging through emails." Consumers need Google AI Plus, Pro or Ultra, and personal accounts in the EEA, the UK, Switzerland and Japan are excluded. Two weeks earlier, on [September 3](https://blog.google/products-and-platforms/products/workspace/voice-features-gmail-docs-keep/), Google announced Gmail Live, a voice mode for finding "specific inbox details just by asking simple questions."

### What this means for you

An assistant reads your text, not your design. A code baked into an image, a deadline that lives only in a banner, a product name that only exists in alt text: all of it is harder to find and quote correctly. Put the offer, the code, the expiry date, the order number and the action in live text.

People are not handing over their inboxes yet. In [Validity's holiday survey](https://www.prnewswire.com/news-releases/nearly-half-of-younger-buyers-will-trust-a-brand-less-by-the-time-the-holidays-end-validity-research-finds-302893607.html), 7% use AI summaries to manage holiday email and 36% want no AI assistant in their inbox at all, though 25% would use one to surface the best deals.

## Deliverability: same rules, fewer signals

### Gmail's requirements held

We found no new Gmail sender requirement in August or September. The [sender FAQ](https://support.google.com/mail/answer/14229414?hl=en) still asks you to keep user-reported spam below 0.1% and never reach 0.3%, and notes that "starting November 2025, Gmail is ramping up its enforcement on non-compliant traffic," with temporary and permanent rejections.

### Postmaster Tools v1 is going away

This is the change that will catch people out. Al Iverson [reported on August 20](https://www.spamresource.com/2026/08/gpt-v1-retirement-and-important-updates.html) that Google had lifted its pause on retiring v1: "GPT V1 is now being phased out." Version 2 "does not contain the reputation indicators that V1 had," so the bad, low, medium and high domain and IP ratings are going with it.

If someone on your team checks that chart every morning, give them a new routine now: spam rate, the v2 compliance status, bounce and deferral codes from your sending logs, and engagement by mailbox provider from your own data.

### Microsoft's ten days

Between August 31 and September 9, Microsoft logged three separate Exchange Online incidents, which [emailexpert pieced together](https://emailexpert.com/microsofts-ten-days-three-exchange-online-incidents-three-causes/) on September 10:

| Dates | Incident | What happened |
| --- | --- | --- |
| Aug 31 to Sep 3 | MO1465074 | An authentication configuration fault hit Exchange Online and other Microsoft 365 services for about 67 hours. |
| Sep 4 | EX1467029 | External mail was deferred with `451 4.7.500 Server busy`, subcode `S77714`. Microsoft blamed an anti-spam model and a throttling rule still firing during recovery. |
| Sep 9 | EX1469649 | Outlook mobile and Outlook for Mac could not connect after a mail-flow update drove up CPU. |

Remember September 4. Microsoft documents `451 4.7.500` as throttling caused by a change in the sender's pattern, so senders looked at themselves first. Then One.com, Qboxmail, Mailjet and Poppulo all reported the same codes across every IP and region. Before you cut volume or pause a domain over Microsoft deferrals, check whether everyone else is seeing them too.

Microsoft is still the hardest big inbox to reach: [Validity's 2026 benchmark](https://www.validity.com/wp-content/uploads/2026/03/2026-Benchmark-Report.pdf) put its 2025 inbox placement at 77.4%, against 89.8% for Gmail and 87.2% globally.

### A blocklist for fake warming

On [September 3](https://www.prnewswire.com/news-releases/validity-launches-heatwave-blocklist-to-combat-unethical-cold-email-practices-and-synthetic-domain-warming-302868287.html), Validity launched Heatwave, a blocklist for domains warmed by networks of fake accounts trading synthetic opens, clicks and replies. It says more than 1 million domains were already listed. If an agency or vendor runs outreach or warming under your name, look your domains up.

### DMARC: published is not enforced

Two vendor studies looked at what DMARC records actually say, not just whether they exist. [1lookup](https://www.1lookup.io/research/email-authentication-2026) checked in September; [EasyDMARC](https://easydmarc.com/blog/ebook/dmarc-adoption-report-2026/) measured a much larger set earlier in the year:

| Domain set | Publish DMARC | Enforce (quarantine or reject) | Source |
| --- | --- | --- | --- |
| Top 5,000 mail-receiving domains | 84.4% | 65.5% | 1lookup, September 2026 |
| 3,000 domains ranked around 500,000 | 65.2% | 29.5% | 1lookup, September 2026 |
| Top 1.8 million domains | 52.1% | 22.9% | EasyDMARC, early 2026 |

A `p=none` record reports spoofing and blocks none of it. Enforcement is also the price of a logo in the inbox: BIMI needs it, and only 15.7% of the top 5,000 domains publish a BIMI record. With phishing climbing into the holidays (more below), getting to enforcement is one of the best October projects you can pick. Our [deliverability guide](/blog/email-deliverability) covers the setup.

## Email platforms opened further to AI agents

The clearest product trend of the period: instead of building one more assistant inside their own app, platforms let agents that live elsewhere reach their data and actions, mostly through the Model Context Protocol (MCP) or official Claude and ChatGPT connectors. Most already had something; this window brought more tools, more write access and new connectors.

| Date | Company | What shipped or was announced |
| --- | --- | --- |
| Aug 12 | Loops | [Workflows API and a Claude connector](https://loops.so/changelog/workflows-api-claude-connector) |
| Aug 31 | Intuit Mailchimp | [Mailchimp connector in Perplexity Computer](https://www.intuit.com/blog/innovative-thinking/tech-innovation/intuit-perplexity-partnership/), alongside QuickBooks |
| Sep 9 | Klaviyo | ["260+ MCP tools and capabilities and 490+ APIs"](https://www.klaviyo.com/newsroom/kbos-2026-headless) available from Claude, ChatGPT and other AI systems |
| Sep 10 | Customer.io | [Agent, CLI and MCP tools that analyze workspace data](https://docs.customer.io/release-notes/2026-09-10-agent-analytics/) |
| Sep 16 | HubSpot | [Breeze Assistant](https://www.hubspot.com/company-news/fall-26-spotlight) that "now takes action" and assigns work to agents |
| Sep 17 | Brew | [Flows](/blog/email-flows): 151 captured email sequences an agent can read over the API and MCP |
| Sep 23 | Brew | [Organization keys](https://docs.brew.new/changelog/posts/organization-keys): one API key or MCP connection for every brand in an organization |
| Sep 28 | Brevo | [Claude connector](https://www.brevo.com/blog/ask-a-question-get-a-campaign-with-the-brevo-connector-for-claude/) that reads contacts and results and saves email and SMS drafts |
| Sep 29 | beehiiv | [Official connector in Claude and ChatGPT](https://product.beehiiv.com/p/paid-recs-beehiiv-ai-and-more) |
| Sep 29 | Salesforce | [Headless Marketing with MCP servers](https://www.salesforce.com/blog/dreamforce-2026-5-ways-marketing-cloud-is-building-a-new-model-for-growth/) and a Campaign Agent for Marketing Cloud |
| Sep 29 | Braze | [Operator Connect](https://martech.org/braze-expands-ai-from-content-creation-to-campaign-operations/), which uses MCP to take Braze's assistant into tools like Claude |

The jobs got bigger, too. Braze's Agentic Standards hands campaign QA to agents, Iterable's [Monitoring Agent](https://iterable.com/blog/fall-2026-product-launch/) "surfaces early signals, explains what happened and why it matters," Salesforce says its Campaign Agent "keeps working" after launch, and Attentive's [Lifecycle Intelligence](https://www.attentive.com/press-releases/attentive-releases-new-ai-pro-and-ai-reporting-functionality-helping-brands-turn-customer-signals-into-higher-value-engagement) adds product-affinity audiences. In August earnings, Klaviyo called itself "the autonomous B2C CRM" and HubSpot "the agentic customer platform for scaling businesses."

One consumer-side detail is worth borrowing. [Engadget notes](https://www.engadget.com/2249396/how-to-let-claude-send-emails/) of Claude's Gmail connector that "by default, Claude asks for your consent before sending any email." That is the right default for marketing too. Once an agent can reach a live list, who approved what matters as much as the writing.

That is how we built Brew's [MCP server](/blog/brew-mcp): over an OAuth connection, a live send waits until a person confirms it, and since September one connection can work across every brand in an organization while each call names the brand it touches. (Disclosure: we compete with several companies in that table. We listed dated, linked announcements and did not rank them.)

## What the numbers say

### Open rates are not comparable across vendors

Every 2026 benchmark reports a different "average open rate," and most of the gap is arithmetic. Some are weighted by volume, some are not, some are medians, and some count the machine opens Apple Mail Privacy Protection generates.

![Bar chart of average open rates: Brew customers at 35.6% in August and September 2026 with machine opens filtered, Selzy's 11.0% weighted average, Brevo's 20.73% rising to 33.87% when Apple Mail Privacy Protection opens are counted, Klaviyo's 31% for campaigns and MailerLite's 43.46%.](/images/blog/state-of-email-open-rate-definitions.png)

*Same metric name, different definitions. Brevo's own figure moves from 20.73% to 33.87% when Apple MPP opens are counted. Brew's 35.6% is what is left after detected machine opens are removed.*

| Source | Reported open rate | How it is measured |
| --- | --- | --- |
| [Selzy](https://selzy.com/en/benchmarks/email-marketing-benchmarks-2026/), Jun to Jul 2026 | 11.0% weighted, 13.6% median | Unique opens over delivered, weighted by volume; 602.2 million emails |
| [Brevo](https://www.brevo.com/blog/email-marketing-benchmarks/), 2025 data | 20.73%, or 33.87% with Apple MPP | Unweighted averages, outliers removed; 175,000+ customers |
| [Klaviyo](https://www.klaviyo.com/products/email-marketing/benchmarks), 2026 report | 31% campaigns, 32.2% flows | Klaviyo customers, 183,000+ in the report text |
| [MailerLite](https://www.mailerlite.com/blog/what-is-good-open-rate-and-ctr-for-email), Dec 2024 to Nov 2025 | 43.46% | 3.6 million campaigns from 181,000+ accounts |
| [Brew](https://docs.brew.new/analytics/key-metrics-and-terms), Aug to Sep 2026 | 35.6% | Brew customer sends; detected machine opens (Apple privacy prefetch, security scanners) and bot clicks excluded by default |

So compare opens only with your own history on the same platform, and set targets on clicks, conversions and revenue per recipient. Then check what your dashboard is counting, because that is where platforms differ most.

That is also how to read our own number. Across Brew customer sends in August and September, 35.6% of delivered emails were opened after we removed the Apple privacy prefetch and security-scanner pixel loads we detect. That is above Klaviyo's 31% and Brevo's MPP-inclusive 33.87%, without machine opens propping it up. It is why we think Brew is the best place to read opens and clicks right now: the filtering runs by default on every send, with nothing to configure, so when the rate moves, it is far more likely that readers did something different. No filter catches every scanner, and our customers are a different group from these vendors' customers, so read it as our data, not a controlled comparison. Our guide to [which benchmarks deserve your trust](/blog/email-marketing-statistics) has the questions to ask of any statistic.

### Clicks tell you more than opens

An open says the subject line and sender earned a look. A click says the email did its job. Two ratios are worth tracking: click rate, the share of recipients who clicked, and click-to-open rate, unique clickers divided by unique openers.

![Two bar charts comparing clicks. Click rate: Brew customers about 15%, Brevo 2.27%, MailerLite 2.09%, Klaviyo campaigns 1.69%. Click-to-open rate: Brew customers 42%, a typical range of 10% to 20% as described by Brevo, and MailerLite 6.81%.](/images/blog/state-of-email-click-rates.png)

*Brew's click rate is derived from its open and click-to-open rates. Bot clicks are filtered out of Brew's figures.*

| Source | Click rate | Click-to-open rate |
| --- | --- | --- |
| Brew customers, Aug to Sep 2026 | About 15% | 42% |
| [Brevo](https://www.brevo.com/blog/email-marketing-benchmarks/), 2025 data | 2.27% for campaigns, 7.39% for automated and transactional | 10% to 20% is typical, it says |
| [MailerLite](https://www.mailerlite.com/blog/what-is-good-open-rate-and-ctr-for-email), Dec 2024 to Nov 2025 | 2.09% | 6.81% |
| [Klaviyo](https://www.klaviyo.com/products/email-marketing/benchmarks), 2026 report | 1.69% for campaigns, 5.58% for flows | Not published |

Brew customers' click-to-open rate was 42%: unique clickers divided by unique openers. Combined with the 35.6% open rate, that works out to about 15 emails clicked for every 100 delivered, and repeat clicks on the same email don't count twice. One caution when you compare click-to-open across platforms: removing machine opens makes the denominator smaller, which pushes click-to-open up. Click rate over recipients doesn't have that problem, and on that measure Brew customers came in at several times the published campaign averages. Link scanners that click every URL can inflate click rates too, which is why Brew filters the bot clicks it detects before counting. If your own click-to-open is falling while opens hold steady, look at the email itself: the offer, the layout and the call to action.

### Automation earns far more than its share of sends

Three platforms' data point the same way, though none proves that turning a campaign into a flow causes the lift:

- [Klaviyo](https://www.klaviyo.com/products/email-marketing/benchmarks): campaigns are 94.7% of sends, yet flows bring in nearly 41% of email revenue, with revenue per recipient nearly 18 times higher. Flow click rate is 5.58% against 1.69% for campaigns.
- [Omnisend](https://www.omnisend.com/resources/reports/2026-ecommerce-marketing-report/), 2025 data from 150,000 brands: automated emails earned $2.87 per send, scheduled campaigns $0.18.
- [Selzy](https://selzy.com/en/benchmarks/email-marketing-benchmarks-2026/), mid-2026: triggered and automated emails had a 31.4% open rate and 6.4% click rate, against 11.0% and 1.2% for mass campaigns.

![Two paired bars comparing share of sends and share of revenue for automated email: Klaviyo flows at 5.3% of sends and about 41% of revenue, and the Omnisend per-send value of $2.87 for automations versus $0.18 for campaigns.](/images/blog/state-of-email-automation-share.png)

*A small share of the volume, a large share of the revenue, in both vendors' data.*

### What holiday shoppers told Validity

Validity's [Holiday 2026 Consumer Survey](https://www.prnewswire.com/news-releases/nearly-half-of-younger-buyers-will-trust-a-brand-less-by-the-time-the-holidays-end-validity-research-finds-302893607.html), out September 30, is mostly about volume. The release gives no sample size or country, so read it as directional:

- 44% get more promotional email over the holidays, and 36% say that volume has made them miss a bill, a shipping notice or another message that mattered.
- One in three say holiday volume alone could make them unsubscribe.
- 47% say trusting the brand already affects whether they open its holiday email, ahead of the 39% who point to discounts.
- 22% say a temporary "opt down" or snooze option would help.

That last one is cheap to act on: "fewer emails until January" keeps a subscriber you would otherwise lose. And when people do leave, frequency is rarely the reason they give. In Selzy's mid-2026 data, 83.5% of about 173,000 unsubscribes with a stated reason picked some version of "no longer interested," and 6.8% said too often. One platform's customers, so treat it as a signal.

### What Mailchimp saw last peak season

Mailchimp's [peak-season analysis](https://mailchimp.com/newsroom/peak-season-marketing-insights/), published September 21, covers more than 44 billion emails and 83 million texts sent from Halloween to New Year's Eve 2025. These are correlations among Mailchimp customers:

- Segmented emails with dynamic content had 11% higher average order value over Black Friday and Cyber Monday.
- Weekend order rates were double weekday rates, while brands sent about 60% fewer messages on weekends. The Sunday between Black Friday and Cyber Monday had 59% fewer emails than Black Friday itself.
- 16.6% of first-time peak-season buyers bought again in the first quarter of 2026, after a median of 26 days.

The repeat-purchase number is the one to plan around. A post-purchase flow that starts after the first holiday order and runs into January covers exactly the window where those second orders happened.

### Retire the $36 ROI figure

The "$36 for every $1" line in so many decks is a [2020 Litmus survey](https://www.litmus.com/wp-content/uploads/2020/09/State-of-Email-Report_Fall-2020.pdf) of what marketers said. The UK DMA's 2026 figure of about £41 per £1 ([up from around £38](https://www.actionrocket.co/blog/dma-email-tracker-2026-key-takeaways-for-email-marketers)) is self-reported too, and in [Mailgun's 2026 survey](https://www.mailgun.com/email-impact-report/chapter/email-roi/) only 46% of senders could measure promotional ROI at all. Put your own revenue per recipient in the plan instead.

## Market moves

| Company | Period and date | What was reported |
| --- | --- | --- |
| Klaviyo | Q2 2026, Aug 5 | [Revenue of $370.6 million](https://investors.klaviyo.com/newsroom/news/news-details/2026/Klaviyo-Delivers-Strong-Q2-as-Autonomous-B2C-CRM-Strategy-Gains-Momentum/default.aspx), up 26%; full-year guidance raised to $1.526 to $1.534 billion |
| HubSpot | Q2 2026, Aug 5 | [Revenue of $911.7 million](https://www.sec.gov/Archives/edgar/data/1404655/000119312526335148/hubs-ex99_1.htm), up 20% as reported |
| Intuit Mailchimp | Q4 FY26, Aug 25 | [Mailchimp is managed as a separate operating segment](https://www.sec.gov/Archives/edgar/data/896878/000089687826000029/fy26q4earningspressrelease.htm) from August 1 and becomes a separate reportable segment in fiscal 2027 |
| Braze | Fiscal Q2 2027, Sep 8 | [Revenue of $227.2 million](https://app.edgar.tools/filing/1676238/0001676238-26-000039/a20260731-brazeincxq227ear.htm), up 26.2%; 2,789 customers |

Klaviyo also agreed to [acquire the team and technology of Agency](https://www.klaviyo.com/newsroom/agency-elias-torres), Elias Torres's AI company, and on September 23 SMS platform Postscript [launched email](https://www.prweb.com/releases/postscript-launches-email-on-a-new-ai-native-retention-marketing-platform-302884359.html). SMS-first and email-first platforms now chase the same retention budget.

## Regulation

### EU AI Act transparency duties apply

Article 50 of the EU AI Act has applied since August 2, 2026, as [Morgan Lewis summarizes](https://www.morganlewis.com/blogs/sourcingatmorganlewis/2026/08/eu-ai-acts-transparency-rules-what-went-into-effect-on-2-august). Providers of tools that generate synthetic content must mark output in a machine-readable way, with a grace period to December 2, 2026 only for systems already on the market before August 2. Deployers, meaning businesses that use those tools, must disclose deepfakes and some AI-written text published to inform the public on matters of public interest. Most promotional copy is unlikely to qualify. A realistic AI image of a person or place in your email might. This is a summary, not legal advice.

### France: the tracking-pixel window closed

The CNIL published its recommendation on email tracking pixels on April 14, 2026, and its [FAQ](https://www.cnil.fr/fr/faq-recommandation-pixels-courriers-electroniques) gave senders until July 14 to inform existing subscribers and let them object. Since then, pixels need consent unless they are used only for deliverability or security and meet every condition, and a pixel that also records the time of the open no longer qualifies. If you mail French recipients, that deadline has passed.

### US: no new click-to-cancel rule yet

A federal appeals court vacated the FTC's click-to-cancel rule on July 8, 2025. The FTC's new comment period closed on [April 13, 2026](https://www.federalregister.gov/documents/full_text/html/2026/03/13/2026-04952.html), and as of September 30 we found no new final rule. CAN-SPAM, including a working opt-out, still applies.

## The Q4 outlook

### Holiday forecasts

| Forecaster | Published | Forecast |
| --- | --- | --- |
| [Adobe](https://news.adobe.com/news/downloads/pdfs/2026/09/adi-holiday-forecast-release-9-26.pdf) | Sep 28 | US online sales of $275.1 billion from November 1 to December 31, up 6.7%; Cyber Monday $15.1 billion; Black Friday $12.9 billion, up 9.2% |
| [Deloitte](https://www.deloitte.com/us/en/about/press-room/deloitte-forecasts-holiday-retail-sales.html) | Sep 10 | Holiday retail sales of $1.70 to $1.71 trillion, up 4.0% to 4.8%; e-commerce up 7.5% to 8.4% |
| [Mastercard Economics Institute](https://www.retailcustomerexperience.com/news/holiday-sales-forecast-predicts-biggest-growth-in-4-years/) | Late September | Retail sales excluding autos and gas up 5.5% from November 1 to December 24; online up 11% |

Two lines in Adobe's release belong on your calendar. It expects $95.8 billion in US online spending in October, up 8%, including $9.9 billion over Prime Day on October 6 and 7. And it expects traffic to retail sites from AI chat and browser assistants to rise 130%, peaking on Thanksgiving. Some shoppers will land on your campaign page without ever opening the email that announced it.

### Phishing is rising into the season

The Anti-Phishing Working Group's [Q2 2026 report](https://docs.apwg.org/reports/apwg_trends_report_q2_2026.pdf) counted 1,069,681 phishing attacks, up 10.1% on the first quarter, with wire-transfer business email compromise up 88%. On September 17, the FBI's IC3 [reported](https://www.ic3.gov/PSA/2026/PSA260917) losses over $1.6 billion from government-impersonation scams since January 2025. Impersonation hurts honest senders twice: subscribers learn to distrust brand email, and mailbox providers filter harder. An enforced DMARC policy is the part you control.

## What to do in October

1. **Retire the v1 reputation chart.** Watch spam rate, Postmaster Tools v2 compliance status, and bounce and deferral codes by provider.
2. **Take DMARC from `p=none` to quarantine, then reject,** once every legitimate sender passes alignment.
3. **Put the facts in live text.** Offers, codes, deadlines and order details should read fine with images off, so assistants and search can find them.
4. **Offer an "opt down"** before peak volume, and make sure one-click unsubscribe works.
5. **Treat October as peak season.** Plan around Prime Day on October 6 and 7, and test weekends and shoulder days before adding weekday volume. Bringing a quiet domain or cold segment back? Ramp it over several days with something like Brew's [gradual send](https://docs.brew.new/create-emails/send-options), not one big blast.
6. **Build the second-purchase flow now,** timed to the four weeks after a first holiday order. Our [Flows library](/blog/email-flows) has 151 real sequences, with the day each message landed, if you want a head start.
7. **Write down your incident check,** so the next September 4 does not trigger a needless volume cut.
8. **Keep receipts and password resets off your marketing domain.** If a promotion dents your marketing reputation, order confirmations should not pay for it. That separation is how [transactional email in Brew](https://docs.brew.new/changelog/posts/transactional-email) works.
9. **Check every email before it ships.** Links, image weight, the unsubscribe link and Gmail's 102 KB clipping limit, on the exact version going out. Brew's [email audit](https://docs.brew.new/create-emails/audit-email) runs those checks for you.

## What we are watching in October

- Siri AI in French, Japanese, Korean, Portuguese and Spanish, which Apple says arrives in October.
- Braze's Decisioning Studio Go, due for general availability on October 14, and Agentic Standards, also due in October.
- Iterable's Nova Conversations private beta, planned for October.
- How fast Postmaster Tools v1 disappears for the remaining accounts.
- Prime Day results, the first real test of Adobe's October forecast.

## New in Brew in August and September

We publish this report, so here is what we shipped over the same two months:

- **[Transactional email](https://docs.brew.new/changelog/posts/transactional-email)** (August). Password resets, receipts and verification codes send from Brew as automations on a transactional-purpose domain, with no unsubscribe link.
- **[Email audit](https://docs.brew.new/changelog/posts/email-audit)** (August). Checks links, images, unsubscribe content, loaded size, copy, client compatibility and accessibility before you send.
- **[Comments](https://docs.brew.new/changelog/posts/comments)** (August). Comment on an email or one element and tag teammates, so review and approval happen on the design.
- **[Unified analytics](https://docs.brew.new/changelog/posts/unified-analytics)** (August). Every send in one list, with per-step numbers for each email in an automation, and machine opens and bot clicks filtered out.
- **[Flows](/blog/email-flows)** (September). 151 real email sequences from other brands, with the day each message landed, in the app or over the API and MCP.
- **[Organization keys](https://docs.brew.new/changelog/posts/organization-keys)** (September). One API key or MCP connection for every brand in an organization.

Everything else is in the [changelog](https://docs.brew.new/changelog/overview).

## How we put this together

We collected announcements, filings, research and regulatory documents published or taking effect between August 1 and September 30, 2026, plus a few older documents where a baseline helps, labeled with their dates. We opened every source and copied figures from the source itself. We left out anonymous acquisition rumors, forecasts we could not trace to the forecaster and statistics we could not find in a primary document. If we missed something or got something wrong, tell us and we will correct the edition and say so.

## Frequently asked questions

### What is The State of Email?

Brew's monthly report on what changed for email marketers: mailbox providers, deliverability, platforms, data, regulation and the season ahead. Every edition links its sources and labels vendor data as vendor data.

### What changed in email marketing in September 2026?

Apple released iOS 27 with Siri AI on September 14, Gmail's AI Overviews in search went global on September 15, Google kept retiring Postmaster Tools v1 and its reputation dashboards, Microsoft had three Exchange Online incidents between August 31 and September 9, and many email platforms expanded what outside AI agents can do.

### Did Gmail change its bulk sender requirements in 2026?

Not in August or September. The spam-rate guidance of below 0.1% and never 0.3% is unchanged, and Gmail has been tightening enforcement since November 2025, including temporary and permanent rejections for mail that does not comply.

### What is a good email open rate in 2026?

There is no reliable cross-vendor answer. Published 2026 benchmarks run from 11% to 43% because they calculate differently and treat Apple Mail Privacy Protection opens differently. Compare against your own history on the same platform, and set targets on clicks, conversions and revenue per recipient. If your platform counts machine opens, your rate looks higher than it is. Brew filters the machine opens and bot clicks it detects by default, and Brew customers averaged 35.6% in August and September 2026 with those removed.

### What is a good click-to-open rate?

MailerLite puts the average at 6.81%, and Brevo describes 10% to 20% as typical. Brew customers averaged 42% in August and September 2026, or about 15% of delivered emails clicked. Platforms that filter machine opens report higher click-to-open rates because the denominator is smaller, so click rate over recipients is the fairer cross-platform comparison.