Tip: Use email composition and mailing tools that work correctly. Make sure your date header is correctly formatted and in the correct time zone. Use an intelligent mailing agent, one which identifies itself in the headers and which isn't heavily used by spammers. Tip: Use an intelligent message id which ties correctly to your system. It won't flag you as a good guy directly, but it will prevent bad guys from successfully masquerading as you. Tip: Using SPF identification for your domain helps. Make sure that if someone checks on the domain of your From address and Reply-To address that these addresses are valid, and the machine that would receive any Reply email can be identified. Tip: Use a domain name which is identified by a verifiable IP address. If you add unnecessary headers to your emails, this can make them look like spam. Likewise, spammers often try to track their spam and guage its effectiveness through tracking headers they add to emails. Spammers need to try to fake out filters by hiding their source and destination if you try to hide your source and destination you'll look like spam too. Don't insert strange Received headers, or any other unwarranted header. If the recipient is a list or a class of people, state so. Make sure the the To header indicates the recipient. Be accurate in who you are (From), and which systems the email goes through, preferably from your own servers, using your own domain name. Even if you do hit an occasional rule, unless your email actually is spam, it shouldn't score high enough to be a problem. If your email isn't spam, you shouldn't be matching the rules. Tip: Don't worry too much about specific rules within SpamAssassin. These guidelines can be useful if you haven't yet sent out your email(s), and want to keep the scores low (or negative) to avoid false-positive problems.

Other Resources – Where else can you look for guidance?.

Newsletter Aids – Your newsletter is confirmed opt-in / double opt-in, never spams, and you want to gain some negative (i.e.

Fixing FPs – Your email was flagged as a spam – how to avoid this next time.

General Guidelines – These guidelines can be useful if you haven't yet sent out your email(s), and want to keep the scores low (or negative) to avoid false-positive problems.

Some Tips for Legitimate Senders to Avoid False Positives

Text spammer between a certain time