This routine verifies that mail services on a DirectAdmin-managed VPS are operational after updates, configuration changes, incidents, or when mail delivery issues are suspected. It is intended to confirm functional health, not to troubleshoot complex mail flow problems.
Scope and intent
- Confirm that core mail services are running
- Validate basic send and receive capability
- Detect obvious configuration or service failures early
- Provide a repeatable, non-destructive verification process
When to run this routine
- After system, DirectAdmin, or mail-related updates
- After a server reboot
- When users report delayed, bounced, or missing mail
- As part of periodic service health checks
Prerequisites
- Root or administrative shell access
- DirectAdmin access
- At least one existing mailbox on the Account Domain
1. Verify mail-related services are running
- Confirm the MTA service is active (Exim or Postfix, depending on configuration)
- Confirm POP3/IMAP service is active (Dovecot)
- Confirm any enabled spam or filtering services are running (e.g., SpamAssassin)
- Ensure no mail service is repeatedly restarting or in a failed state
2. Confirm DirectAdmin mail service status
- Log in to DirectAdmin
- Navigate to the service or admin status area
- Verify mail services report as running
- Restart a mail service from DirectAdmin only if status is unclear or stale
3. Validate local mail delivery (send test)
- Send a test message from one local mailbox to another local mailbox
- Confirm the message appears in the recipient inbox
- Verify timestamps are correct and no excessive delay is present
4. Validate outbound mail capability
- Send a test message from a local mailbox to an external address you control
- Confirm the message is received
- Check headers for obvious delivery errors or rejection notices
5. Validate inbound mail capability
- Reply from the external mailbox back to the local mailbox
- Confirm the message is received without delay
- Ensure it is not incorrectly flagged as spam
6. Review mail logs for anomalies
- Scan recent mail logs for delivery failures, authentication errors, or repeated retries
- Look for signs of queue buildup or blocked outbound connections
- Confirm no sudden spike in rejected or frozen messages
7. Sanity-check mail queue
- Confirm the mail queue is not growing unexpectedly
- Investigate any stuck or deferred messages at a high level
- Do not flush or delete queued mail unless you are performing incident recovery
8. Record results
- Note the date and reason this routine was run
- Record any anomalies observed, even if resolved
- Document follow-up actions if deeper investigation is required
Completion criteria
- Mail services are running and stable
- Local and external send/receive tests succeed
- No unexplained errors or queue growth remain
Next step — based on your current state:
- If mail issues were detected or suspected, proceed to Log Review Routine.
- If this check followed a risky change, proceed to After Server Update Verification Checklist.
- If all services are healthy, return to normal operations or your scheduled maintenance cadence.