GlockApps was the product ChatGPT and Gemini named most often when we asked about email deliverability tools: it appeared in 5 of the 6 buyer questions we ran on 2026-08-04. No other tool matched it. We put each question to ChatGPT and Gemini with one live web search, then recorded every product named and every source domain cited. GlockApps missed only one question out of six.
Mailtrap came second, named in 4 of the 6 answers. It also appeared once more under a separate label, "Mailtrap Email Delivery Platform," which the assistants used only in the bare "best" query, so in the raw data Mailtrap is split across two names. Behind those two sat a five-way tie at 3 of 6: Mailreach, MxToolbox, Postmark, Warmup Inbox and ZeroBounce each turned up in exactly half the answers.
The tail was thin. Across the six questions the assistants named 20 distinct products, but 9 of those 20 were named in only a single question. The shortlist a buyer sees is not stable: it swings hard on how the question is worded, and that is the most important thing this measurement shows.
The shortlist changed with the question
The bare "best email deliverability tools" question returned eight names: GlockApps, Mailtrap Email Delivery Platform, Postmark, Mailgun, TrulyInbox, Warmup Inbox, Inbox Radar by Saleshandy and EasyDMARC. This was the only one of the six questions where Mailtrap showed up under its "Email Delivery Platform" label.
"Best free email deliverability tools" returned just five names, and it was the single most different list of the six: Mailtrap, MxToolbox, EasyDMARC, MailGenius and ZeroBounce. GlockApps, which led 5 of the other questions, disappeared entirely from the free query. MailGenius was named here and in no other question.
"Most affordable email deliverability tools" returned a seven-name list that barely touched the free one: TrulyInbox, Inbox Radar by Saleshandy, MxToolbox, Everest by Validity, GlockApps, Mailreach and Warmbox. Out of the roughly 11 unique names across the "free" and "affordable" questions, only 1 product, MxToolbox, appeared in both. "Free" and "affordable" read like the same intent to a person, but to the assistants they were almost different categories.
Nine products hung on a single question each. Folderly and Warmy.io appeared only in "small teams." Google Postmaster Tools appeared only in "what should I use." MailGenius appeared only in "best free." Everest by Validity and Warmbox appeared only in "most affordable." Mailgun Optimize and Unspam.email appeared only in "recommendations." Mailtrap Email Delivery Platform appeared only in "best." Change the adjective, change the answer.
Where the answers came from
Two domains fed all six answers: mailtrap.io and reddit.com were each cited in 6 of 6. Then came emailtooltester.com and saleshandy.com at 5 of 6, and amplemarket.com and mailercheck.com at 4 of 6. Seventeen source domains appeared in total.
Community threads carried real weight. Reddit was cited in all 6 answers and Quora in 2 of 6. Forum posts written by shoppers are being read straight back to the next shopper. Independent roundups mattered too: emailtooltester.com, a comparison site that does not sell a deliverability tool of its own, was cited in 5 of 6.
The sharpest signal is in the vendor domains. mailtrap.io was cited in all 6 answers, and Mailtrap was named in 4 of them. Mailtrap published the roundup the assistant read, and got itself named inside it. saleshandy.com (5 of 6), easydmarc.com (3 of 6) and trulyinbox.com (3 of 6) did the same: their own domains fed the answers, and their products, Inbox Radar by Saleshandy, EasyDMARC and TrulyInbox, were each named twice.
But the more useful lesson is the reverse. GlockApps was named in 5 of 6 answers while glockapps.com was cited 0 times. GlockApps wins by living inside other people's roundups and Reddit threads, not by getting its own site crawled. Being named is about presence in the pages buyers trust, not about self-citation.
And a plain absence worth stating: no software review directory appeared. G2, Capterra, TrustRadius and Software Advice were cited 0 times across all six answers. In this category, the assistants are not reading the classic review sites.
What we would do to get named here
Being named is decided by the source list, not by market share. GlockApps did not need the largest brand; it needed to be in the pages the assistants pulled. Across our six questions those pages were consistent: Reddit (6 of 6), the mailtrap.io roundup (6 of 6), emailtooltester.com (5 of 6), saleshandy.com (5 of 6), then amplemarket.com and mailercheck.com (4 of 6 each).
So if we were marketing a deliverability tool, we would work those exact sources: get into the emailtooltester.com comparison, earn a genuine Reddit thread, and land in the vendor roundups that already rank, instead of buying a directory profile that was cited 0 times. And we would re-measure per question, because the "best free" and "most affordable" lists shared only 1 product.
The full list, counted
| Product | Named in | Share |
|---|---|---|
| GlockApps | 5 of 6 | 83% |
| Mailtrap | 4 of 6 | 67% |
| Mailreach | 3 of 6 | 50% |
| MxToolbox | 3 of 6 | 50% |
| Postmark | 3 of 6 | 50% |
| Warmup Inbox | 3 of 6 | 50% |
| ZeroBounce | 3 of 6 | 50% |
| EasyDMARC | 2 of 6 | 33% |
| Inbox Radar by Saleshandy | 2 of 6 | 33% |
| Mailgun | 2 of 6 | 33% |
| TrulyInbox | 2 of 6 | 33% |
Two brands were double-labelled in the raw data, and we kept them as the assistants said them rather than merging the counts: Mailtrap was also named once as "Mailtrap Email Delivery Platform," and Mailgun (named in 2 of 6) was also named once as "Mailgun Optimize."
Glotier does not sell an email deliverability tool, so we are correctly absent from all six of these answers. We did not name ourselves, and we would not put ourselves in a list we do not belong in. But running a category exactly this way, the precise products, the precise source domains, the precise gap between "free" and "affordable," is what Glotier does for whatever category you do sell in. The check is free, needs no account, and takes about a minute.