Fixing "Sender verify failed" Errors

When sending email through MXroute's SMTP servers, you may encounter the error message "Sender verify failed". This error has a very specific meaning, but the correct resolution depends on your specific setup and use case.

Understanding the Error

The "Sender verify failed" error occurs because of how MXroute's mail servers validate sender addresses:

How It Works

1. When you add a domain in DirectAdmin's Domain Setup, the server adds it to its list of locally managed domains
2. When sending email with a FROM address using one of these domains, the server checks: "Can I deliver mail to this address locally?"
3. If the answer is no, sender verification fails

Important Points

• MX records don't matter - The server only checks its local configuration
• External hosting is irrelevant - Even if you host the domain elsewhere, the server still checks locally
• It's about local delivery - The server must be able to deliver to the FROM address on that specific MXroute server

Available Solutions

Depending on your situation, one of these approaches will resolve the error:

Remove the sending domain from DirectAdmin

Navigate to Domain Setup and remove the domain. This is appropriate when:

• You don't receive email for this domain on MXroute
• The domain is hosted elsewhere for incoming mail

Rename the domain in DirectAdmin

In Domain Setup, rename the domain (e.g., add "-old" suffix). Consider this when:

• You want to keep the domain data but stop the server from managing it
• You may need to restore the domain later

Create the sender email address

Add the exact FROM address as a mailbox in DirectAdmin. This works when:

• You want to keep the domain on MXroute
• You need to receive bounce notifications
• You're using the domain for both sending and receiving

Set up email forwarding

Create a forwarder or catch-all for the domain. Use this approach when:

• You don't need a full mailbox for the sender address
• You want to forward bounces elsewhere
• You need flexibility in handling multiple sender addresses

Disable local email routing

Go to DirectAdmin → Email Routing, select the domain, and uncheck "Use this server to handle emails for [domain]". This is ideal when:

• You need the domain in DirectAdmin for other purposes
• You want to send as this domain but receive mail elsewhere

Prevention Tips

• Only add domains to DirectAdmin that you intend to receive mail for on MXroute
• Review your domain list periodically and remove unused entries

Still Having Issues?

If none of these solutions work:

1. Verify you're using the correct SMTP authentication credentials
2. Check that the FROM address is properly formatted
3. Ensure you're not hitting any sending limits
4. Contact MXroute support with the exact error message and timestamp