Mailgun for email deliverability
Deliverability is the loop that decides whether mail lands: watch bounces, verify domains, read delivery stats, and diagnose failures. Mailgun's official open-source server is our second pick of four here, and it carries the deepest dedicated deliverability tooling in the group, domains, tracking, queues, and webhooks all addressable from an agent.
It lands at second rather than first because the picks are close and the lead pick edges it for the most common workflow, but Mailgun is the strongest when the work is genuinely about delivery mechanics: an agent can send a message and then immediately inspect the domain, tracking, and queue state behind it.
How Mailgun fits
For sending, post-v3-domain-name-messages dispatches the mail, while get-v3-domains-domain-name-messages-storage-key retrieves a stored message and post-v3-domains-domain-name-messages-storage-key resends it. The deliverability surface is the differentiator: get-v4-domains and get-v4-domains-name list and detail sending domains, put-v4-domains-name-verify verifies authentication, and get-v3-domains-name-sending-queues reads queue status when mail is backing up. Tracking is fully addressable through get-v3-domains-name-tracking plus put-v3-domains-name-tracking-click, put-v3-domains-name-tracking-open, and put-v3-domains-name-tracking-unsubscribe, and get-v3-domains-domain-webhooks reads the event hooks that report bounces and complaints.
The honest limits: the listed tools cover domains, tracking, queues, storage, and webhooks rather than a single dedicated suppression-list endpoint, so suppression work runs through webhooks and message inspection. Resend is the cleaner pick for a developer-first sending experience with less operational surface. Postmark is strong on transactional inbox placement and is often the more opinionated deliverability choice. Brevo bundles contacts and campaigns alongside sending. Reach for Mailgun when domain verification, tracking configuration, and queue diagnostics are the core of the deliverability work.
Tools you would use
| Tool | What it does |
|---|---|
| post-v3-domain-name-messages | Send an email. |
| get-v3-domains-domain-name-messages-storage-key | Retrieve a stored email. |
| post-v3-domains-domain-name-messages-storage-key | Resend an email. |
| get-v4-domains | Get domains. |
| get-v4-domains-name | Get domain details. |
| put-v4-domains-name-verify | Verify Domain. |
| get-v3-domains-name-sending-queues | Get messages queue status. |
| get-v3-domains-name-tracking | Get tracking settings. |
| put-v3-domains-name-tracking-click | Update click tracking settings. |
| put-v3-domains-name-tracking-open | Update open tracking settings. |
FAQ
- Can an agent verify a sending domain with the Mailgun server?
- Yes. get-v4-domains and get-v4-domains-name list and detail your domains, and put-v4-domains-name-verify runs domain verification, so an agent can check and confirm authentication directly as part of deliverability work.
- How does it help diagnose why mail is not arriving?
- get-v3-domains-name-sending-queues shows whether messages are stuck in the queue, get-v3-domains-domain-webhooks reads the hooks that report bounces and complaints, and the stored-message tools let an agent retrieve and resend a specific message while investigating.