Email delivery services: AI search visibility ranking (2026)
How AI search engines rank email delivery services by visibility and citations. 20 brands measured monthly across Google AI Mode: which brands the AI names in answers, which domains it cites as sources, and how the leaders compare. Email delivery services used by product, marketing, and engineering teams to send transactional and bulk email with APIs, SMTP infrastructure, analytics, and deliverability tooling. Composite score: 70% visibility (% of AI answers naming the brand) + 30% citation rate (% citing the brand's domain). Full methodology →
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When buyers ask AI engines like ChatGPT, Claude, or Perplexity which email delivery service to use, Mailgun comes up most often, appearing in 12.5% of all brand mentions across the category. Mailtrap and Postmark round out the top three. Mailgun also leads on citations, meaning AI engines not only name it but actively point to its content as a reference source.
The sources AI engines pull from most in this category include youtube.com, mailtrap.io, sendlayer.com, reddit.com, and zapier.com. Several of those are either the brands themselves or third-party aggregators and community forums. That pattern matters because it means rankings here reflect a mix of brand-owned content authority and independent third-party validation, with community discussion on Reddit and workflow-focused coverage on Zapier carrying real weight.
For a buyer using this page, the practical takeaway is that AI visibility tracks closely with third-party credibility. A brand ranking well here has typically earned positive coverage on review aggregators, developer forums, and integration-focused platforms. If you are evaluating a lesser-known provider from this list, check whether it appears in those same third-party sources, since AI engines weight that external validation heavily when forming recommendations.
At a glance
What we observed in this categoryauto-generated
Mailgun holds the top composite score at 16.2, ahead of Mailtrap at 15.0 and Postmark at 12.5, but the category average visibility sits at just 2.5 percent, meaning the gap between the leader and the field is narrower in absolute terms than composite scores suggest. Every brand in the top 10 lists Google AI Mode as its top engine, confirming this is a single-engine category with no meaningful diversification across AI platforms. The compressed scores across ranks 3 through 5 (all at 12.5 or 11.2) indicate no dominant authority has emerged below Mailgun.
Mailtrap is the sharpest anomaly in the data: it carries a 50.0 percent citation rate yet 0.0 percent visibility, meaning AI cites it heavily as a source but does not surface it prominently when naming brands. SMTP.com shows a similar pattern with 37.5 percent citation and 0.0 percent visibility. Mailgun inverts this, with 12.5 percent visibility but only 25.0 percent citation. Amazon SES presents the opposite extreme, reaching 12.5 percent visibility with 0.0 percent citation, suggesting it is named by AI but its own domain is not used as a reference source.
The top cited sources list reveals that AI anchors heavily on third-party and community content: youtube.com, reddit.com, and zapier.com all appear alongside brand domains like mailtrap.io, sendlayer.com, and twilio.com. Sendlayer appears as a top cited source despite not ranking in the top 10 by composite score, indicating citation influence does not map cleanly onto brand ranking. Twilio appears as a cited source likely via its Sendgrid product, yet no Sendgrid entry appears in the ranked brand data, a notable gap in the audit coverage.
Movers & shakers since last refresh
Biggest visibility fallers
-
Mailgun 25% → 12% · rank #2 → #1-12pp
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Mailtrap 12% → 0% · rank #1 → #2-12pp
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Postmark 25% → 12% · rank #3 → #3-12pp
The ranking
| # | Brand | Visibility | Citation | Top engine |
|---|---|---|---|---|
| 1 |
mailgun.com
|
12% | 25% | Google AI Mode |
Mailgun leads with a composite score of 16.2 and 12.5 percent visibility, but its visibility has fallen 12.5 points from the previous period with no citation change. |
||||
| 2 |
mailtrap.io
|
0% | 50% | Google AI Mode |
Mailtrap holds the highest citation rate in the dataset at 50.0 percent yet records 0.0 percent visibility, a direct contradiction between being cited and being named. |
||||
| 3 |
postmarkapp.com
|
12% | 12% | Google AI Mode |
Postmark sits at 12.5 percent on both visibility and citation, making it the most balanced of the top five, though both metrics fell 12.5 points from the prior period. |
||||
| 4 |
brevo.com
|
12% | 12% | Google AI Mode |
Brevo matches Postmark exactly at 12.5 percent visibility and 12.5 percent citation, with no movement data shown, suggesting a stable but unremarkable AI presence. |
||||
| 5 |
smtp.com
|
0% | 38% | Google AI Mode |
SMTP.com carries a 37.5 percent citation rate, third highest in the top 10, but its 0.0 percent visibility means AI references it without actively surfacing it as a recommended brand. |
||||
| 6 |
aws.amazon.com
|
12% | 0% | Google AI Mode |
| 7 |
elasticemail.com
|
0% | 25% | Google AI Mode |
| 8 |
mailjet.com
|
0% | 12% | Google AI Mode |
| 9 |
mailersend.com
|
0% | 12% | Google AI Mode |
| 10 |
courier.com
|
0% | 12% | Google AI Mode |
| 11 |
socketlabs.com
|
0% | 0% | Google AI Mode |
| 12 |
resend.com
|
0% | 0% | Google AI Mode |
| 13 |
bird.com
|
0% | 0% | Google AI Mode |
| 14 |
pepipost.com
|
0% | 0% | Google AI Mode |
| 15 |
sendgrid.com
|
0% | 0% | Google AI Mode |
| 16 |
bird.com
|
0% | 0% | Google AI Mode |
| 17 |
mailchimp.com
|
0% | 0% | Google AI Mode |
| 18 |
netcorecloud.com
|
0% | 0% | Google AI Mode |
| 19 |
bird.com
|
0% | 0% | Google AI Mode |
| 20 |
smtp2go.com
|
0% | 0% | Google AI Mode |
Sources AI engines trust in this category
Across the 8 buyer-intent queries we ran on email delivery services, these are the domains Google AI Mode cited most often. If you're not on this list — or if your competitors are — that's a concrete PR / linkbuilding target.
How to read this ranking
Four things worth knowing before you act on the numbers above. These are the same definitions across every industry page — for category-specific observations, see the What we observed section above (where available) and the per-brand insights inline in the ranking.
Visibility = being named
A brand's visibility % is the share of AI answers that mention it by name in the response prose. This is who AI engines actively recommend to the buyer. More on visibility →
Citation rate = being trusted
Citation rate is the share of AI answers that include the brand's domain as a clickable source link. This is what the AI treats as authoritative evidence, different from being named. More on citation rate →
Top engine differs by brand
The "top engine" column shows which AI surface each brand performs best on. Big gaps between a brand's score across engines usually points to specific content or schema gaps. How AI engines pick sources →
Rankings move month to month
AI engines re-crawl and re-rank on shorter cycles than classical search. We re-audit every brand on this list at least every 30 days and refresh this page automatically. How AI search ranking works →
Get your own email delivery services brand audited
The brands above were curated from public market-leader lists. Want the same measurement against your own brand — including the queries you appear on, which competitors get named instead, and a prioritised fix list? Run a free preview.
Frequently asked about email delivery services AI visibility
Who leads AI visibility in email delivery services?
Mailgun leads with a composite score of 16.2 and 12.5 percent visibility, ahead of Mailtrap at 15.0 and Postmark at 12.5. However, Mailgun's visibility dropped 12.5 points from the previous period.
Which brands are cited most by AI in email delivery services but have low visibility?
Mailtrap (50.0 percent citation, 0.0 percent visibility) and SMTP.com (37.5 percent citation, 0.0 percent visibility) are the clearest examples of high citation paired with zero named visibility.
What sources does AI cite most when discussing email delivery services?
The top cited sources include youtube.com, mailtrap.io, sendlayer.com, reddit.com, and zapier.com, indicating AI leans heavily on third-party review and community content rather than vendor pages alone.
Which engine dominates AI visibility for email delivery services?
Google AI Mode is the top engine for every brand in the top 10, with no other engine appearing in the data, making this a single-engine category in the current audit.
How competitive is the email delivery services category in AI visibility overall?
The category average visibility is just 2.5 percent across 20 brands, and even the top-ranked brand reaches only 12.5 percent, showing the category is highly fragmented with no dominant AI presence.
Are any brands gaining AI visibility in email delivery services?
The data shows no visibility risers in the current period. Mailgun, Mailtrap, and Postmark are all recorded as fallers, each dropping 12.5 points in visibility from the previous period.