University of Waterloo -- Rejected Email

You're visiting this page because mail you've sent to someone at the University of Waterloo has been rejected. Probably the mail server that sent your mail has been documented as a bulk junk mail source, or "spammer." The server may not be generating the bulk mail itself. It could be that the software at your site is configured to relay mail from anywhere to anywhere, and someone -- from another site entirely -- has exploited your site's facilities. Your site gets a bad reputation as an open relay, and you find yourself unable to send mail to us, as well as to many other sites.

You, of course, are not a spammer. The fact that you're reading this means that you're a real person -- not some mindless, mechanical, mailing machine -- and you'd like to be able to send mail to your friend, colleague, or workmate at UW. And we'd like to help.
Getting your site off the list:

There are several mechanisms for rejecting mail. The one that rejected yours may have been listed in the rejection message itself. You may also enter the IP address of your mail server (which looks something like and should be in the rejection message) in a couple of the public blacklist testing sites to see whether your mail server is on any of several commonly-used anti-spam blacklists.

Show the We are not accepting mail from ... or Your host hostname [nn.nn.nn.nn] ... message to your site administrator, or send a copy to your Internet service provider's technical support helpdesk. Encourage him/her/them to resolve the problems that resulted in the "spammer" designation, so he/she/they can get the site removed from everyone's rejection lists. If you've had trouble sending email to us, you may also find that other places are rejecting mail from your site.

Visit (and encourage your site administrator to visit) the appropriate website(s) to learn about the problem, its solution, and how to request your site's removal from the anti-spam blacklist(s).

Note: The databases we use are maintained by the above organizations, not by the University of Waterloo. Users and organizations submit additions to these databases from around the world. Your site's system administrator can request deletions, once the cause of the complaint has been addressed.

FAQ for on-campus users

Are you reading my mail?
No! The decision to accept or reject a piece of mail is based solely on where it's coming from and where it's going. Nobody is checking the contents of your email.
How can I get in touch with someone at a blocked site?
You can probably send a message to a user at a blocked site without any trouble, but they may not be able to reply.
Is there something I can do so that all my mail arrives?
Individual users can request that their mail not be filtered; all mail to their userid could then get through, including any mail currently being rejected due to blacklisting.
I can't believe that XYZ Corporation is a spammer.
They may not be; their mail machine may have gotten a bad reputation for some other reason. Let us know if there's a group we should accept mail from, and we'll add it to our exceptions list. (Let us know nicely of course, because we're not a mindless, mechanical, mailing machine either. )
I've got a userid; why can't I send mail from home?
If you get the error message "Relaying denied" when sending mail from your computer at home, you're probably trying to relay your outgoing mail through an on-campus machine, rather than through your Internet Service Provider's outgoing mail (SMTP) server. Many on-campus machines will not allow relaying of mail from off-campus sites and many ISPs will not allow you to send mail except through the ISP's own mail servers.

Problems? Let us know!
Updated 1 March 2007, UW Information Systems and Technology