Error Description

SMTP error 510 is a permanent or "5xx" error code returned by a mail server to indicate that it has rejected an email message because the recipient's mailbox is unavailable or has exceeded its storage quota. This error signifies that the recipient's mailbox is full or otherwise inaccessible.

What's Causing This Error?

SMTP error 510 is typically caused by one or more of the following reasons:

• Mailbox full: The recipient's email mailbox has reached its storage limit and cannot accept additional email messages until some space is cleared.
• Mailbox suspended: The recipient's email account has been suspended or disabled, making it temporarily or permanently inaccessible.
• Email routing issues: Problems with email routing or domain configuration can also lead to SMTP error 510, preventing email delivery.

How to fix SMTP Error 510?

• Contact the recipient: If you receive SMTP error 510, it's advisable to contact the recipient and inform them about the issue. They may need to clear space in their mailbox, reactivate their account, or address any other access issues.
• ‍Verify recipient mailbox status: Check if the recipient's email account is indeed full or suspended. If suspended, they will need to resolve the suspension with their email service provider.
• Investigate routing or domain issues: If the error is related to routing or domain configuration, it may require the attention of the recipient's email administrator or hosting provider to resolve the problem.

SMTP Error 510 Examples

Example 1: "510 5.2.2 recipient@example.com: Mailbox is full and cannot accept new messages."

Example 2: "510 5.7.0 Recipient's email account is suspended. Email delivery denied."

Example 3: "510 5.4.3 Email routing issue. Unable to deliver the message to recipient@example.com."