# What would stop a mail server?

**URL:** <https://forum.kirupa.com/t/what-would-stop-a-mail-server/249331>\
**Category:** Uncategorized\
**Created:** [January 17, 2008, 4:42pm UTC](https://forum.kirupa.com/t/what-would-stop-a-mail-server/249331 "2008-01-17T16:42:12Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![GeTSm0keD](https://avatars.discourse-cdn.com/v4/letter/g/e480ec/32.png) [@GeTSm0keD](https://forum.kirupa.com/u/GeTSm0keD)\
**Post date:** [January 17, 2008, 4:42pm UTC](https://forum.kirupa.com/t/what-would-stop-a-mail-server/249331/1 "2008-01-17T16:42:12Z")

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hi,

I have a windows 2003 server, on IIS6, and a plesk CP.  
at first my email was workin fine. but then I installed coldfusion8 and updated my plesk CP from 8.2 to 8.3 and now I get email errors. in the plesk CP I get:

\*Warning: Unable to send notification: mail() failed: mail() [\<a href=‘function.mail’\>function.mail\</a\>]: SMTP server response: 550 Requested action not taken: mailbox unavailable or not local

\*and if I try to use my Horde webmail for my domain names, I get:

\*There was an error sending your message: unable to add recipient [fakename@fakesite.com]: Invalid response code received from server

\*what would be a few things I could check into to make sure they are properly configured?