I'm getting a lot of email bounced back, help! How can I fix this problem?

Your email could be bouncing back to you for a variety of reasons. Here are just a few:

1. The email address you are sending to is no good. You might get a error, "unknown user"
2. The email address you are sending to is full, and will not receive new messages.
3. It has blocked the email for anti-spamming purposes.
4. (Most common)Their email server is too busy to accept email.

We have been getting a lot of complaints on reason #4.

Our mail server issues fairly specific error messages, for example:

The following recipient(s) could not be reached:

Error Type: SMTP

Remote server ( issued an error.

hMailServer sent:

Remote server replied: Remote server closed connection.

Tried 5 time(s)


The message above is quite descriptive, indicating the IP of the recipient server, and noting that every of the 5 times which we attempted connection the recipient server issued an error and closed the connection. Our mail servers are configured to try once every 20 minutes for a total of 5 attempts to deliver to the recipient server.

Just a few possible causes could be:

- They are blocking email from your IP address, or your domain.
- The mail is being sent to them with a "reply to" of a null sender, or a malformed email address. (Some server admins do this to try to block spam).
- The mail is being sent to a generic name like "unknown recipients", and the real recipient is listed in the BCC. The destination server could be blocking this because it could be junk mail.
- The destination server is trying to verify the sending email addres is valid. (again, trying to block spam).
- The domain has bad DNS MX records.
- The destination server is down, or too busy to accept connections at the time.

How to troubleshoot:

Try sending an email to a hotmail, yahoo, or similar account. If you can send email to several domains except one or two, then it's clear that the destination server is the culprit, possibly because of one of these reasons. This is especially true if you only have intermittent issue delivering messages to the user or domain in question. You will need to contact the administrator of the destination mail server.

But, I can send them email fine from my other email account with another provider.

You may have happened to email them at a time when their email server was NOT too busy. Spam and email viruses are at an all time high, and are over 10 times what they were just a year ago. Many mail servers, including Microsoft, hotmail, etc, are overburdened with having to handle 10 times as much load, and can be so busy, that sending mail servers can simply NOT get an email through to them.Our mail servers for example block hundreds of thousands of connections from known spam sources in a matter of hours.



Article ID: 274, Created On: 8/28/2003, Modified: 6/9/2009

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