Mail Filtering

In the interests of good Internet citizenship, efficient use of bandwidth, and professional courtesy, USENIX filters inbound email for unsolicited commercial email and virus email.

Inbound email is filtered according to the following process:

The identity of the sending machine is checked against several blacklists. Senders listed in these blacklists are not permitted to send email to USENIX addresses. If your email was rejected for this reason, you will receive an error message of the form:

550 Rejected - MAPS - see
550 Rejected - SPAMHAUS - see

The message contents are also checked using a variety of rules that identify unsolicited commercial email (UCE). Email that is rejected by one of these rules will result in an error message of the form:

550 Rejected - DCC - see

If you were directed to this page by one of the above error messages and would like more information about why your email was rejected, or you believe it was rejected in error, please use our Web form to contact the postmaster.


Email filters in use include: