Outlook Express error 550

[xeroxxe]

#550 Requested action not taken: mailbox unavailable ##

Just get someone getting this message when they try to send mail, any ideas to fix this problem? Anyone seen it before? They have sent mail to other people its just this one email adress having problems with.

[Jamo]

Definition of the error message is:


My brain hasn't worked today!

[powdarrmonkey]

Definition of the error message is:

550 - Relaying not allowed

No, the error is just as the message says. It is from the mail server responsible for the final destination of that mail, and it's telling you that it's not allowed to leave mail for that address - commonly, the mailbox is over quota or has been disabled for some reason. Contact the recipient by some other means.