|Mail abuse home | Receiving spam | E-mail blocked (in or out) |
|Spam from our customers | Our filtering methods | Acceptable use policy|

We reject email which does not conform to the standards for mail server communication. We also reject email from any IP Address which is listed in any of the following public blacklists:

We also maintain our own local blacklist of IP addresses which have sent obvious forgery information to our mail server. This list automatically detects trojaned computers which spammers are exploiting as well as email viruses which send directly from the infected computer to our mail server. In addition, we maintain a list of domain names which appear in spam reported to us from our users and are obviously not forgeries (ie. the sender domain is also the domain used in a link in the content of the email).

Finally, we have written and maintain our own software which extracts the domain names used in URIs in the content of the email. These domains are checked against our local lists, as well as the OB and WS lists published by the public SURBL blacklist.

Each method of filtering and blacklist we use must meets a certain expectation of accuracy. The more aggressive a filter is, the more legitimate emails it will also block. The lists we use are actively maintained and have a very low false positive ratio. Any method of filtering which generates excessive false positives is immediately removed from the system until an adequate replacement can be found. At no time do we use blacklists which heavily support the "punishment" of service providers for hosting spammers.

With few exceptions, all filtering policies issue a rejection code to the sending mail server with a verbose description of why, or how to contact our abuse department. When this rejection is issued, the sending mail server is supposed to contact the sender and inform them that we have not accepted the email. Unfortunately, not every email server is configured properly or handles rejections in a user friendly manner. In such cases, the sender may be misinformed of why the email was rejected or not receive notification at all. Software used to send mailing lists also behave in a variety of ways. Some ignore the rejection and continue to send to us, while others will unsubscribe the email address without informing anyone. Since we enabled filtering of domains listed in email content, we've noticed several mailing lists which unsubscribe the user instead of recognizing that the user account is still there but doesn't like something about the content of the email. It is our hope that over time, many more mailing lists will be aware of spam filters and handle rejections is the best manner possible. Meanwhile, we do handle all requests from senders and customers alike to whitelist any legitimate mailing list servers which occasionally have issues with rejections.