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I Ran 1,000 Email Deliverability Tests. Here's What Works In 2026

https://www.youtube.com/watch?v=ByrOheLnWUY

TLDR Warm email deliverability depends on strong domain and IP reputations, clean lists, recipient engagement, and ongoing inbox-placement testing. Use proper DNS records, remove invalid or unengaged contacts, tailor messages to Gmail and Microsoft, and keep early emails simple and conversational; results vary by sender and delivery service, so test your own campaigns rather than relying on fixed rules.

Key Insights

1. Build a trustworthy sending foundation first

Before changing your email copy, check the reputation of both your sending domain and IP address, since Gmail and Microsoft use these signals to filter messages. Review SPF, DKIM, DMARC, and MX records, and check for blacklist listings; BIMI is an optional additional record. If reputation is poor, correct technical issues and rebuild trust gradually through careful warm-up and consistent sending. A deliverability-focused provider or a properly configured Amazon SES connection may help, but no sending service guarantees inbox placement.

2. Keep your CRM list clean and engaged

Screen new contacts for invalid, disposable, or high-risk email addresses before adding them to nurture campaigns. Automatically suppress or remove contacts who bounce or report spam, and consider pausing follow-up when someone replies. Reverify your list periodically—about every three months is one suggested cadence—because addresses can become invalid over time. A smaller, engaged list is generally a safer foundation than repeatedly mailing a large, unverified one.

3. Make the first nurture email simple and conversational

Start a new sequence with a straightforward message that explains why you are reaching out and invites a reply. Avoid leading with promotional language, numerous links, or elaborate formatting while you are trying to establish engagement. A natural question can encourage a real response and help build a relationship before later sales messages. Keep transactional notices distinct from marketing emails, and use clear, direct language for payment or account updates.

4. Adapt to provider-specific inbox behavior

Gmail and Microsoft do not handle email identically, so a message that reaches one inbox may land in the other provider’s Junk folder. Where practical, tag contacts by email provider and use those segments to compare placement and engagement. Treat Gmail’s Updates tab as an inbox destination rather than assuming only the Primary tab counts as success; the summarized tests reported stronger opens in Updates than in Primary. Also check Microsoft placement after delivery, since messages may be moved to Junk shortly after they arrive.

5. Test placement instead of relying on universal rules

Run inbox-placement tests with representative Gmail and Microsoft accounts before making a change to a campaign. Test one factor at a time—such as the sending route, subject line, links, images, or footer—so you can tell what affected the result. Findings in the source were mixed: some wording changes did not reliably improve placement, and performance varied by sender and delivery path. Use the results to develop rules for your own domain, list, and email service rather than treating any single tactic as guaranteed.

6. Use formatting and advanced tactics cautiously

Promotional emails that combine prominent images and links may be more likely to land in Gmail’s Promotions tab, and the source reports that exposed URLs without “https://” or “www” performed better in a small test. These results are limited observations, not dependable rules, so validate them against your own messages and preserve clear, usable links where recipients need them. The source also describes hidden “ghost” text as an experimental tactic for one-off promotions, but it is not recommended for drip sequences and should not be treated as a substitute for good reputation or consent. Keep payment and other transactional messages free of hidden text and oversized marketing disclaimers.

Questions & Answers

What is the transcript’s overall focus?

It explains how to improve warm-email deliverability—such as newsletters, promotions, and nurture sequences—so messages are more likely to reach Gmail and Microsoft inboxes. The advice is not intended for cold email.

Which factors most affect whether warm emails reach the inbox?

Sending IP and domain reputation are major factors. Providers also consider DNS authentication, list quality, recipient engagement, sending practices, and message content. Check reputation and DNS records before trying to solve deliverability problems by changing copy.

What steps are recommended for improving domain and IP reputation?

Check that the domain and IP are not blacklisted, configure SPF, DKIM, DMARC, and MX records (and optionally BIMI), and rebuild poor reputation through warm-up and time. A warm-up tool that connects through SMTP may help.

Why does the speaker recommend Amazon SES for some GoHighLevel senders?

The speaker says Amazon monitors its shared IPs and may remove users who generate excessive bounces or spam complaints. In the speaker’s tests, mail sent through Amazon SES reached Google and Microsoft inboxes when the same messages sent through Kit landed in Microsoft Junk. Results can still vary.

How should marketers manage and maintain CRM email lists?

Screen new contacts for invalid or disposable addresses, tag contacts by provider, and suppress or remove contacts who bounce, report spam, or reply. Reverify the list about every three months; the speaker notes that self-hosted Reacher can verify up to 10,000 addresses per day for free.

How should the first email in a nurture sequence be written?

Keep it simple, avoid links and promotional language, and ask a question that encourages the recipient to reply. Build engagement and trust before sending more promotional messages.

How do Gmail’s inbox categories compare in the speaker’s tests?

Gmail Updates had the best reported open rate at 28%, compared with 22% for Primary and unclassified messages and 19% for Promotions. The speaker therefore treats Updates as a successful inbox destination, not as spam.

How can marketers test inbox placement, including Microsoft delivery?

The transcript recommends using Consulty.ai’s inbox-placement test to see whether messages land in Gmail Primary, Promotions, or Spam, and to check whether Microsoft moves a message to Junk after a few minutes. Paid users can run unlimited tests, and the API can be used with GoHighLevel or an AI agent.

What content and formatting changes affected placement in the reported tests?

Results varied. Promotional subjects or wording and product listings tended to move Gmail messages to Promotions, while conversational reply prompts or less promotional subjects sometimes reached Primary. A long, legal-style explanation of why a recipient received an email often moved messages from Promotions to Updates. Using both a large image and a link often led to Promotions; removing “www” or “https://” from an exposed URL moved all 11 tested messages to Primary. Other changes—such as removing words like “free” or “discount,” reducing links, or simply asking for a reply—did not reliably improve placement.

What does the transcript say about hidden or “ghost” text?

The speaker reports that carefully designed hidden text may help placement, especially at Google. In tests for one-off promotional campaigns, it reached Gmail Updates in all 11 Google and Microsoft tests and the inbox in all nine tests. The speaker describes it as an advanced technique and does not recommend it for drip sequences; it should also be omitted from straightforward payment notices.

Why can Microsoft placement tests be misleading?

Microsoft’s AI may move a message to Junk shortly after delivery, so a test that checks too soon can produce a false positive. Placement also depended strongly on the sender and delivery path in the speaker’s tests.

What is the speaker’s main recommendation for developing deliverability rules?

Continuously test messages using your own sending setup rather than relying only on fixed guidelines. Results can differ by sender, content, delivery path, and recipient relationship, and placement tests may not reflect the trust built with an established audience.

Summary of Timestamps

The speaker explains that reaching Gmail and Microsoft inboxes has become more difficult in 2026 as providers use AI, updated DNS requirements, and evolving filters. The advice is specifically for permission-based warm email, such as newsletters and nurture campaigns—not cold outreach.

Sending IP reputation is a major factor in deliverability. Shared or newly assigned IPs may have a poor reputation, so the speaker recommends using a deliverability-focused service or connecting GoHighLevel to Amazon SES. In the speaker’s tests, Amazon SES improved placement in both Google and Microsoft, though no sending route guarantees inbox delivery.

Domain reputation matters alongside IP reputation. Before changing email copy, check that the sending domain and IP are not blacklisted and have a healthy history. If reputation is poor, rebuild it gradually through warm-up and time.

The speaker recommends warming up the sending setup and checking DNS records, including SPF, DKIM, DMARC, and MX; BIMI is presented as optional. Free DNS and blacklist checkers can help identify technical issues, but fixing the underlying reputation should come before editing email content.

Inbox placement depends on more than whether an email reaches the inbox or spam. The speaker says more than 1,000 tests examined how links, footers, wording, and formatting affected placement, and notes that Google and Microsoft apply different rules.

Gmail’s Updates tab performed well in the speaker’s tests, with a 28% open rate, compared with 22% for Primary and unclassified messages and 19% for Promotions. The point is that Updates can still be a valuable inbox destination, even when testing tools do not label it simply as “inbox.”

Microsoft can be harder to test because its AI may move a message to Junk shortly after delivery. The speaker describes using Consulty.ai’s placement test to check Gmail tabs and confirm whether Microsoft keeps a message in the inbox after a few minutes.

Healthy CRM lists support better deliverability. The speaker recommends screening new contacts for invalid or disposable addresses, tagging them by provider, and automatically suppressing or removing contacts who bounce, report spam, or reply.

The first message in a nurture sequence should be simple and conversational: avoid links and promotional language, and ask a question to encourage a reply. The speaker also recommends reverifying lists every three months and mentions Reacher as an open-source option for checking up to 10,000 addresses per day when self-hosted.

Test results suggest that placement can depend on small copy choices, but there is no universal wording fix. Teasing another email or listing products tended to push Gmail messages toward Promotions, while a conversational prompt or less promotional subject sometimes reached Primary.

A long, legal-style explanation of why someone received an email often moved messages from Promotions to Updates in the tests, although it made the email less appealing. By contrast, removing words such as “free” or “discount,” reducing links, or simply asking for a reply did not reliably improve placement.

Microsoft results varied substantially by sender and delivery route: the same domain and copy went to Junk through Kit.com but reached the inbox through GoHighLevel connected to Amazon SES. The speaker emphasizes building trust and engagement before sending promotions, since placement tests may not represent an established relationship.

For transactional payment notices, the speaker recommends keeping the message straightforward and avoiding hidden text or large disclaimer blocks. These notices should not be formatted like marketing campaigns.

In additional tests, combining a large image with a link often sent messages to Gmail Promotions. Removing “www” or “https://” from an exposed URL moved all 11 tested messages to Primary, while hidden “ghost” text helped one-off promotional emails reach Updates in all 11 Google and Microsoft tests and the inbox in all nine inbox tests.

The speaker cautions that hidden-text techniques are advanced and are not recommended for drip sequences. The broader lesson is to keep testing deliverability rules against your own audience, content, and sending setup instead of relying on fixed guidelines.

The video closes with an invitation to join the Lead Gen Secrets community for email-marketing and AI resources, guides, and coaching. The speaker also promotes deliverability services and asks viewers to like, subscribe, and comment.