> No, if the recipient is not existent the "MUST" return a 5xx > error, that is a > permanent error. Is it possible that some MUA's look at the wording of the error message in addition to the error code? I.e. Outlook/Eudora/etc... For example when sendmail has an unknown user it reports: "550 5.1.1 <[EMAIL PROTECTED]>... User unknown" and when xmail reports a user unknown it says: "550 Mailbox unavailable <[EMAIL PROTECTED]>" Both have the same error codes (550) however each has something different after the error code... Is it possible that the MUA is reading the wording after the error code and having problems? Just a thought... Riaz...
