Bounced Email Messages

When you send an email message the SMTP (Simple Mail Transport Protocol) server attempts to send it to the destination (the TO:, CC: and BCC: addresses). Your email may go through many different SMTP servers until it reaches one or more destination POP3 (Post Office Protocol) servers. If the email is successfully delivered to a POP3 server, it will wait for the recipient to read the message using his email client.

Sometimes a message cannot be delivered to the recipients POP3 server for whatever reason. In this instance an SMTP server may attempt to retry a few times (say once every four hours for a day) just in case the server is down or unavailable. The delay between retries, number of retries and even whether or not a retry is attempted depends upon how the SMTP server is configured.

Some SMTP servers may return a "retry" message back to you when this happens, other may not. There is nothing you can do about it, but it's often nice to know that a message has not reached it's destination. In fact, it can be useful to examine these messages because it's possible that the message is delayed because you typed in an incorrect email address. This would alert you to resent the message with the correct address.

If it happens that the message cannot be delivered for some reason, then a "bounce" message will be returned to you. These messages take many different forms, depending entirely upon the configuration of the server which is attempting to deliver the message.

Read the message and it will, believe it or not, tell you exactly why the email was rejected.

Mailbox is full

You've sent an email to someone and they have too many messages in their mailbox. This often happens when someone goes on vacation, if they only check their mail infrequently, or if their mailbox has been email bombed.

Message exceeds size limit

The message is too large to be received at the users mailbox. Some ISP's limit the size of messages and others limit the size of a mailbox.

Improper forwarding causing mail loop

This is a very interesting type of error. What it means is a message is in a loop. For example, an email account "A" sends to "B", which forwards to "A" which forwards to "B" and so on.

User Unknown

You've tried to send an email to an unknown user on the domain. Check your spelling. It's possible the account has been deleted. If you are responding to a spam message, it's probably the username is fake.

Connection timed out or refused

This means the POP3 server was too busy or was having problems. Try the email message later.

Domain not found

The part of the email address after the "@" sign is incorrect. Check your spelling.