SMTP Error 442:

What does it mean? And How to resolve this error.

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Error Description

SMTP error 442 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 or email account is temporarily unavailable. This error signifies that the recipient's email address is valid, but there is a temporary issue preventing the message delivery.

What's Causing This Error?

SMTP error 442 can be caused by various temporary issues, including::

  • Server maintenance: The recipient's email server may be undergoing maintenance or experiencing temporary downtime, making the mailbox temporarily unavailable.
  • Mailbox locking: Another process or user might be accessing the recipient's mailbox, preventing the email delivery at that moment.
  • Account syncing: The recipient's email client or server may be in the process of syncing or updating, temporarily locking the mailbox.

How to fix SMTP Error 442?

  • Wait and retry: SMTP error 442 often indicates a temporary issue. The best approach is to wait for a while and retry the email delivery later. The recipient's mailbox should become available again.
  • Verify recipient's email address: Ensure that the recipient's email address is spelled correctly and is complete. This error typically implies that the recipient's email address is valid but temporarily inaccessible.
  • Contact the recipient: If the issue persists or if you consistently encounter SMTP error 442 when sending emails to a specific recipient, you may want to contact the recipient via an alternative method (e.g., phone) and inform them of the issue. They can check the status of their email account or contact their email provider for assistance.

SMTP Error 442 Examples

Example 1: ""442 4.2.1 recipient@example.com: Mailbox temporarily unavailable. Please retry later."

Example 2: "442 5.3.2 recipient@example.com: Mailbox currently locked for maintenance. Try again in an hour."

Example 3: "442 5.7.3 recipient@example.com: Mailbox syncing in progress. Email delivery delayed."