GlockApps vs Mail-Tester
Ongoing inbox placement and DMARC analytics versus quick single-message preflight tests.
What matters for developers picking email infrastructure
The question here is which one a backend engineer would rather operate. That means SDK depth in the language already in use, whether a retry can safely be replayed, how much the event log tells you when a customer says the email never arrived, and whether the pricing curve stays sane as volume grows.
| Priority | GlockApps | Mail-Tester |
|---|---|---|
| DX score | 7/10 | 8/10 |
| SDKs | None | None |
| Idempotency keys | No | No |
| Operating since | Not published | Not published |
| Event stream | Yes | No |
| Best published rate per 1,000 | Tiers not published in comparable form | Tiers not published in comparable form |
| Webhooks | No | No |
| Deliverability | Not a sender. Measures inbox placement and DMARC alignment so teams can diagnose deliverability problems before blaming the ESP. | Not a sender. Scores one message at a time and helps identify obvious authentication, blacklist, and SpamAssassin issues. |
| Free tier | Free plan with 2 Inbox Insight tests once and 10,000 DMARC messages/mo | 3 tests free within the last 24 hours via the web interface |
For a developer-owned stack running password resets, receipts, and magic links shipped from application code, the split is even: GlockApps takes event stream, Mail-Tester takes developer experience. Neither pulls ahead on this audience's priorities. On free tier, GlockApps offers Free plan with 2 Inbox Insight tests once and 10,000 DMARC messages/mo against 3 tests free within the last 24 hours via the web interface from Mail-Tester. That ordering reflects this audience. Weigh the same table differently and the answer changes.
Side by side
| Feature | GlockApps | Mail-Tester |
|---|---|---|
| DX score | 7/10 | 8/10 |
| SDKs | None | None |
| Webhooks | No | No |
| Deliverability | Not a sender. Measures inbox placement and DMARC alignment so teams can diagnose deliverability problems before blaming the ESP. | Not a sender. Scores one message at a time and helps identify obvious authentication, blacklist, and SpamAssassin issues. |
| Free tier | Free plan with 2 Inbox Insight tests once and 10,000 DMARC messages/mo | 3 tests free within the last 24 hours via the web interface |
| Tagline | Inbox placement testing plus DMARC analytics. | Simple send-to-test-address spam score checks. |
| Starts at | $59/mo billed annually for Essential | $50 for 500 tests, or larger prepaid test packs |
| Pricing model | tiered | pay-as-you-go |
| API | Yes | Yes |
| SMTP | No | No |
| Templates | none | none |
| React Email | No | No |
| Inbound | No | No |
| Multi-tenant | Yes | No |
| Idempotency | No | No |
| Dedicated IP | No | No |
| Best for | Growth and marketing teams that regularly test inbox placement across Gmail, Outlook, and other mailbox providers. | Developers and marketers who need a quick preflight check for a specific message. |
GlockApps
- ›Combines spam testing with DMARC analytics
- ›Free plan includes enough to run a first diagnostic
- ›Credit packs are available for teams that do not want a subscription
- ›Subscription pricing is higher than simple DMARC monitors
- ›Inbox tests are only a sample, not a guarantee of every recipient inbox
- ›Annual billing is needed for the lowest published monthly price
Mail-Tester
- ›Very fast manual diagnostic
- ›Free tests cover occasional checks
- ›Paid API and iframe options exist for product integrations
- ›Prepaid test packs do not expire
- ›No ongoing monitoring unless integrated manually
- ›One test does not represent every mailbox provider
- ›Interface is intentionally simple rather than polished