Does anyone know where I can get a list of the recommended error codes and their translations for bounced and returned mail messages.  I am looking for ways to interpret the following type of codes...

  ----- Transcript of session follows -----
... while talking to mail.crl.com.:
>>> RCPT To:<[log in to unmask]>
<<< 553 <[log in to unmask]>... we do not relay
550 <[log in to unmask]>... User unknown

Something like a list of numbers followed by a better translation.  Especially when I try to figure out the difference between a full mailbox and a server failure.

Any help?  TIA

Paul Rice
mailto:[log in to unmask]