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SMTP Error 450

Category: Other
Tags: # # #

Description: Requested mail action not taken: mailbox unavailable (e.g., mailbox not found, no access, or command rejected for policy reasons).

What does this mean?

Generally errors ending with 0 are going to be the least specific. This error is no exception. This has many meanings or specific possibilities. The most common possibilities include:

  • The recipient mail server no longer has the specified email account.
  • The email account does not have proper permissions to receive email.
  • The recipient mail server rejected your request due to blacklisting or filtering.

How to fix SMTP Error 450?

Hopefully the exact error you received gives a more descriptive reason. If not, here’s a few suggestions to try:

  1. Ensure the email account does exit.
  2. If you have alternative contact method for the user, contact them making them aware of the issue.
  3. Check your mail server’s IP address for blacklisting.
  4. Check your email message for “spammy” content.
  5. If you have an attachment, try sending with out one.

SMTP Error 450 Examples

450 Please try again later
SMTP Error 450 5.2.3 Msg Size greater than allowed by Remote Host