Troubleshooting Email Delivery

When email delivery fails, determine whether the problem affects incoming mail, outgoing mail, or both.

Incoming mail checks

Verify:

• the mailbox is reachable
• credentials are valid
• incoming server settings are correct
• the expected message actually reached the mailbox
• the Helpdesk channel is enabled
• no mailbox rule moved or deleted the message

Outgoing mail checks

Verify:

• SMTP host and port
• security mode
• authentication credentials
• sender permissions
• provider delivery limits
• recipient address

Review logs and errors

Use available delivery logs or error messages to distinguish authentication, connection, DNS, provider, or application problems.

Controlled testing

Send a test message in both directions using a known recipient.

Good practices

Do not repeatedly change multiple settings at once. Change one verified item at a time so the real cause can be identified.