7 Tips For Getting Your Emails Through Spam Filters

Monday, April 21st, 2008

When developing websites, you’ll often be tasked with launching emails from your web server to a variety of destinations, whether they’re internal or external. These emails can be confirmation emails, newsletters, etc. However, sometimes they get caught in various spam filters, and since many spam filters are different, it’s hard to pinpoint what you need to do for each one to get your email through. Here are a few tips that can help you get to your destination.

1 - Keywords
This seems like the biggest culprit. If at all possible, stay away from keywords such as Sale, 20% Off, Limited Time Offer, etc. There’s no definite list, but you can use your judgment. Of course, there’s also the obvious: Forex, Rolex, Viagra, etc.

2 - Text Alternate (or simple HTML alternate)
If you’re launching HTML emails, be sure to include a text-only alternate (and vice-versa). Not only does it help with getting your email through filters, but also with recipients who check their emails on mobile devices.

3 - SMTP
If at all possible, use an SMTP server to launch emails instead of using unauthenticated email.

4 - Link Destinations
Have a look at your link destination, avoid including hyperlinks with the following destinations:

An IP
A port number
A deep folder architecture (eg. http://www.pat-burt.com/insiders/content/avi/download/getit.html)
Subdomains

5 - Recipient List
If at all possible, try to send the emails to recipients individually. Multiple recipients in a To, CC or BCC field can start to get flagged as bad news.

6 - To and From Fields
This is different for each programming language, but make an effort to list the sender’s and the recipient’s name or organization, instead of uniquely the email.

7 - External Applications
External email distributors such as Campaigner will actively make sure you’re email doesn’t get blocked by taking a few of the precautions mentioned above for you. They are also more likely to be making sure that their origin/IP isn’t blacklisted to most spam filters. It gets riskier if you decide to go with cheaper Walmart hosting and run the risk of getting flagged by other users who share the same server.

Hope that helps, that’s all for now.