Most errors when sending or receiving email come from a few common causes. Below are the most frequent error messages and how to fix them.
Common error messages
| Error | Meaning | What to do |
|---|---|---|
Mailbox full / 452 4.2.2 | Your mailbox quota is full. | Follow the "Mailbox full" steps below. |
535 Authentication failed | Wrong username or password. | Use your full email address as the username and reset the password in the panel. |
550 Relaying denied | SMTP authentication is off. | Turn on outgoing server authentication. |
550 User unknown | The recipient address does not exist. | Check the recipient address. |
554 Message rejected as spam | The receiving server treated the email as spam. | Check your SPF, DKIM, DMARC records. |
| Sending times out | Your internet provider blocks port 25. | Set the outgoing port to 465 (SSL) or 587 (STARTTLS). |
Sending limit exceeded | The hourly sending limit was exceeded. | Wait an hour; use a newsletter service for bulk mail. |
Mailbox full
- Log in to Webmail and delete old emails with large attachments.
- Empty the Trash and Sent folders.
- If you use IMAP, move old emails to a local folder on your computer (a PST file in Outlook).
- If needed, increase the quota: in Plesk Mail > email address > Mailbox size, in cPanel Email Accounts > Manage > Allocated Storage Space.
Still not solved?
Add the full text of the bounced email and the time you got the error to a support ticket. With this information we can find the problem quickly.
Need help? Open a support ticket from your client area or call +90 216 348 35 03.
