Most errors when sending or receiving e-mail have a few common causes. Below you can find the most frequent error messages and their solutions.
Mailbox quota is full
Symptom: E-mails sent to you bounce; the sender gets a Mailbox full, Quota exceeded or 452 4.2.2 error.
Solution:
- Log in to webmail, delete old e-mails with large attachments and empty the Trash and Sent Items folders.
- If you use IMAP, move e-mails to a local folder on your computer (in Outlook, "On My Computer" / PST).
- You can raise the quota as far as your plan allows: in Plesk under Mail > e-mail address > Mailbox size, in cPanel under Email Accounts > Manage > Allocated Storage Space.
Common error messages
| Error | Meaning | What to do |
|---|---|---|
535 Authentication failed | Wrong username or password. | Use the full e-mail address as the username and reset the password in the panel. |
550 Relaying denied / Relay access denied | SMTP authentication is off. | Turn on "Outgoing server requires authentication" in your e-mail program. |
550 User unknown / No such user | The recipient address does not exist. | Check the recipient address. |
554 Message rejected as spam | The receiving server marked the e-mail as spam. | Check your SPF, DKIM and DMARC records. |
| Sending times out | Your internet provider blocks port 25. | Set the outgoing server port to 587 (STARTTLS) or 465 (SSL). |
Sending limit exceeded | The hourly sending limit was reached. | Wait an hour; use a newsletter service for bulk mail. |
Still not solved?
Open a support ticket with the full text of the bounced e-mail and the time you got the error. With this information we can find the problem quickly.
