& Our recent efforts to reduce the amount of spam assailing both your inbox and our email servers have been quite successful. Since we added every email account into Postini, we’ve experienced a drastic reduction in spam volume. In fact, Postini now blocks over 1 gigabyte of spam (approximately 165,000 messages) per day.

However, many have noticed that some obvious spam is still slipping through.

We’ve investigated why this is happening and discovered that many of these messages are being spoofed so it looks like they are coming from email accounts on our “global” approved senders list. Postini will always deliver any message sent from an approved address. [unless, incidentally, that address is in a user's Blocked Senders list]

Spoofing is an increasingly common (and increasingly annoying) spam tactic using a fake “from” field in an email, erasing the true address and replacing it with another. You may have noticed that you sometimes get spam mail which appears to come from yourself, or others tell you that they received a spam message from you – it looks like your account has been hijacked, but in reality it’s just email spoofing at work. If you’re interested, this is a great article which describes spoofing and how it works (it’s a quick read and highly recommended for all to understand better the ever-growing dangers of email): http://www.windowsecurity.com/articles/Email-Spoofing.html.

In any case, there were roughly 100 email domains approved at the global level in Postini. We have removed all of them to avoid this problem in the future, and you should now receive less obvious spam at your mailbox. If you’d like to take a quick look at the list of these and add them to your own personal approved senders list, you can find it here: http://helpdesk.coloradocollege.edu/index.php/email-domains-removed/

(you do not need to do this to receive email from these senders; only do it if you want them to bypass your filter completely).

One more spam tip: there are several filter categories in your Postini account, each with different levels. By far the most important filter category is “Bulk Email.” We recommend setting the bulk email filter to the 2nd level to start with (it should be set there by default), and the other filters only to the first level. If spam still slips through regularly, adjust the bulk filter setting up one level and then see how it goes. Keep making this adjustment until the spam stops or is very rare – only increase the levels of the other filters if it’s needed after the bulk filter is at the maximum level

For information about how to log in to Postini, reset your Postini password if unable to log in, and how to use the features, see our guide

As always, please let us know if you have any questions!