Delivery Status Notification

From Ubiquity Web Hosting Wiki

Deliver status notifications are often sent from a receiving email server when there is a problem. These emails should not just be disregarded, as they generally tell you exactly what the problem may be. Scan this message for a message similar to one of the following messages that begins with Remote host said.

Remote host said: 550 Requested action not taken: mailbox unavailable

This means that your message reached the receiving email server, but may mean that this exact email address doesn't exist / was mistyped, is full, or is temporarily disabled.

Remote host said: 550 5.7.1 Rejected: mail.mycompany.com listed at relays.ordb.org

Your domain name or IP address has been listed in a blacklist database that this particular provider uses in filtering deliverable email - in this case, relays.ordb.org

Remote host said: 551 Requested action not taken: mailbox full

Their mailbox is full.

Remote host said: 552 Requested action not taken: exceeded storage allocation

Your email / attachments were too large for this account to receive.

Remote host said: 553 sorry, that domain isn't in my list of allowed rcpthosts 

Your domain name will need to be placed on a white list with the receiving provider to effectively send emails to this address.

Remote host said: 553 bad reverse dns

Something about your reverse DNS settings are causing this message to get rejected.

Remote host said: 554 delivery error: Sorry, your message to __________ cannot be elivered.  This account is over quota. 

Their email address is over their allotted disk space.

Generally a bounce message status will also tell you whether or not it plans to continue making attempts to deliver the email, or if it's giving up immediately. This depends completely on how their email server is configured.