# Mail-Tester alternatives: what AI models name instead, October 2026

GTM AI Recommendation Index, October 2026 Edition. 224 of the 252 answers in the 1 category where Mail-Tester holds a standing named it neither first nor as an alternative; these are the first choices those answers made. Page: https://gtm-ai-index.com/vendors/mail-tester/alternatives/

## Named instead, most often (every category and segment added)

- GlockApps: 52
- Validity Everest: 35
- Google Postmaster Tools: 12
- Litmus: 9
- MailReach: 7
- Instantly: 6

## Email deliverability and testing tools

**Small business**: 69 of 84 answers did not name Mail-Tester (Mail-Tester is #5 of 15 at 5%).

- GlockApps: first choice in 19 of those 69
- Google Postmaster Tools: first choice in 8 of those 69
- Litmus: first choice in 4 of those 69
- Mailtrap: first choice in 4 of those 69
- Email on Acid: first choice in 3 of those 69
- Instantly: first choice in 3 of those 69
- MXToolbox: first choice in 3 of those 69
- MailReach: first choice in 3 of those 69

**Mid-market**: 72 of 84 answers did not name Mail-Tester (Mail-Tester is #5 of 12 at 5%).

- GlockApps: first choice in 29 of those 72
- Google Postmaster Tools: first choice in 4 of those 72
- MailReach: first choice in 4 of those 72
- Folderly: first choice in 2 of those 72
- Microsoft SNDS: first choice in 2 of those 72
- Validity Everest: first choice in 2 of those 72
- Allegrow: first choice in 1 of those 72
- EmailListVerify: first choice in 1 of those 72

**Enterprise**: 83 of 84 answers did not name Mail-Tester.

- Validity Everest: first choice in 33 of those 83
- Litmus: first choice in 5 of those 83
- Everest: first choice in 4 of those 83
- GlockApps: first choice in 4 of those 83
- Validity Engage: first choice in 4 of those 83
- Instantly: first choice in 3 of those 83
- Mailgun: first choice in 3 of those 83
- SendGrid: first choice in 3 of those 83

Published under CC BY 4.0. The output is the models' output; nothing here is a recommendation by the index.