Postal vs Mailgun
Both are alternatives to SendGrid. Here's how they stack up — verified facts, no spin.
Also searched as Mailgun vs Postal — same comparison, one verdict.
Postal
Run your own mail server, properly — MIT, and complete.
Postal is a full self-hosted mail platform: sending, receiving, bounce handling, click and open tracking, DKIM signing and a web interface — the parts you would otherwise assemble from Postfix, OpenDKIM and a database. MIT, around 17k stars. It is the only option here where addresses never leave your infrastructure, which for GDPR-sensitive senders is not a preference but a requirement. The honest warning: running a mail server well is a real discipline, and reputation is unforgiving of mistakes.
Mailgun
The established competitor — strong on validation and routing.
Mailgun is SendGrid's long-standing rival with a comparable feature set and reputation, plus two things it does distinctly well: email address validation before you send, and inbound routing that parses received mail into your application. Proprietary and hosted, priced per volume with a small free allowance. Listed for the same reason as Render on the Heroku page — many teams comparing this category are choosing between managed vendors, and the honest comparison includes the obvious alternative rather than assuming everyone will self-host.
Side by side
| Postal | Mailgun | |
|---|---|---|
| Sovereignty Score | 94 | 31 |
| Open source | Yes | No |
| Self-hostable | Yes | No |
| Local-first | Yes | No |
| License | MIT | Proprietary (hosted service) |
| Pricing | Free and open source. You supply the server and the IP reputation. | Volume-based with a small free allowance; paid tiers from about $15/month. Checked 2026-08-05. |
Postal edges it on the Sovereignty Score, but the right pick depends on the trade-offs below.
Postal
Strengths
- +MIT with no enterprise carve-out
- +Recipient addresses never leave your infrastructure
- +Full platform — sending, receiving, bounces, tracking, DKIM
- +No per-email cost at any volume
Trade-offs
- −You own IP reputation, and warming takes weeks of care
- −Running mail well is a genuine specialism
- −Blocklists are unforgiving of configuration mistakes
- −No shared warmed pool to fall back on
Mailgun
Strengths
- +Strong deliverability record over many years
- +Address validation catches bad addresses before you send
- +Genuinely good inbound routing and parsing
- +Detailed logs and analytics
Trade-offs
- −Proprietary and hosted
- −More expensive than SES for straightforward transactional mail
- −Pricing tiers are harder to read than they should be
- −Support quality varies by plan
Related alternative guides
Facts verified 2026-08-05. Licenses and pricing change — spotted something out of date? That's a correction we want.