250 2.6.0 queued mail for delivery exchange 2013

A classic issue!

The error "250 2.6.0 queued mail for delivery" in Exchange 2013 typically indicates that the email has been successfully received by the Exchange server, but it's being held in the queue for delivery. This can happen for a variety of reasons, including:

  1. Mailbox issues: The recipient's mailbox may be full, or there may be a problem with the mailbox's configuration.
  2. Transport rules: Exchange has a feature called Transport Rules that can hold emails in the queue if they match certain conditions.
  3. Anti-spam and anti-malware filters: These filters may be holding the email in the queue for further analysis or to prevent delivery.
  4. Network connectivity issues: Problems with the network connection between the Exchange server and the recipient's mailbox can cause emails to be held in the queue.
  5. Mailbox database issues: Corruption or issues with the mailbox database can cause emails to be held in the queue.

To troubleshoot this issue, you can try the following steps:

  1. Check the Exchange queue: Use the Exchange Management Shell to check the queue for the specific email. You can use the command Get-Queue -Identity <queue name> to view the queue details.
  2. Check the recipient's mailbox: Verify that the recipient's mailbox is not full and that there are no issues with the mailbox's configuration.
  3. Check Transport Rules: Review the Transport Rules configuration to ensure that there are no rules that are holding the email in the queue.
  4. Check Anti-spam and Anti-malware filters: Verify that the filters are not holding the email in the queue.
  5. Check network connectivity: Verify that the network connection between the Exchange server and the recipient's mailbox is functioning correctly.
  6. Check the mailbox database: Run a database consistency check using the command Isinteg -s <server name> -fix to identify and fix any database issues.

If none of these steps resolve the issue, you may need to contact Microsoft Support or a qualified Exchange administrator for further assistance.