Alternatives · Deliverability
Email on Acid alternatives
As of Nov 13, 2026, the best Email on Acid alternative for most people is GlockApps (2.2 GPA), third in our ranking of email verification and deliverability tools. The best free one is Mail-Tester (2.8 GPA). The catch, in its listing's words: "Free web interface: 3 tests per 24 hours, results kept for 7 days."
Email on Acid compared with 5 alternatives: Inbox Monster, GlockApps, MailGenius, Mail-Tester and Validity Engage.
Email on Acid is a paid product with a free trial, starting at $99 per month. 3 of the 5 alternatives are free or have a free plan.
Listings checked up to Nov 13, 2026 · Where the facts come from
Black Friday: is there a Email on Acid sale?
At a glance
| Tool | Price | Free plan | Runs on |
|---|---|---|---|
| Email on AcidThis tool | Free trial · from $99/mo | Trial only | Web |
| Inbox Monster | From $3,750/yr | No | Web |
| GlockApps | Free plan · from $59/mo | Yes | Web |
| MailGenius | Free plan · from $23/mo | Yes | Web |
| Mail-Tester | Free plan · from $10/mo | Yes | Web |
| Validity Engage | Paid | No | Web |
Price against what you get
Email on Acid starts at $99 a month and scores 2.3 out of 4 on features, ease of use and platforms. 1 of the 4 alternatives on this chart scores higher and starts lower: Mail-Tester.
GlockApps and MailGenius start lower without scoring higher.
Features, ease of use and platforms, averaged
What paid plans start at, a month (each step along is roughly double) →
- The best score at each price
- Has a free plan
- No free plan
How each one differs from Email on Acid
Inbox Monster
Email rendering previews and inbox placement testing
- Inbox Monster starts at $3,750 per year and up (creative suite).
- Inbox Monster also covers dMARC.
Suits: Enterprise email teams that need rendering and placement in one place
GlockApps
Inbox placement testing with DMARC analytics and uptime monitoring
- GlockApps starts at $59 per month, billed annually ($85 monthly).
- GlockApps has a free plan, which Email on Acid lacks.
- GlockApps also covers dMARC.
- GlockApps does not cover reports and email campaigns, which Email on Acid does.
Suits: Senders who want to see where a campaign lands before it goes out
MailGenius
Email spam-score and deliverability tester with DNS checkers
- MailGenius starts at $23 per month for 60 email tests, billed yearly ($29 billed monthly).
- MailGenius has a free plan, which Email on Acid lacks.
- MailGenius also covers dMARC.
- MailGenius does not cover reports and email campaigns, which Email on Acid does.
Suits: Marketers checking a campaign for spam triggers before sending
Mail-Tester
Send an email to a test address and get a spam score out of 10
- Mail-Tester starts at $10 per month for 50 tests; or $5 once for 10 tests.
- Mail-Tester has a free plan, which Email on Acid lacks.
- Mail-Tester does not cover email campaigns, which Email on Acid does.
Suits: Checking one newsletter or sending setup before a send
Validity Engage
Inbox placement and sender reputation monitoring for brands
- Validity Engage also covers dMARC.
- Validity Engage does not cover reports, which Email on Acid does.
Suits: Large senders that need inbox placement data by mailbox provider
Limits worth knowing in Email on Acid
- The pricing page says current customers will move to Mailgun Inspect from June 2026, and that old previews and tests are not carried over.
- Annual-plan customers migrate at the end of their current term.
- Basic has no accessibility, spam or link checks; those start at Premium.
- It does not send email; the FAQ says you need a separate sending service.
Common questions
What are the alternatives to Email on Acid?
The alternatives to Email on Acid in this directory are Inbox Monster, GlockApps, MailGenius, Mail-Tester and Validity Engage. Each one has a side-by-side comparison with Email on Acid.
Is there a free alternative to Email on Acid?
Yes. GlockApps, MailGenius and Mail-Tester have a free plan alongside paid ones.
When were these prices checked?
Each listing shows its own date. On this page they run from Oct 18, 2026 to Nov 13, 2026. Vendors change prices without notice, so confirm on their site before you buy.