Email marketing is a powerful, inexpensive method of reaching potential customers. However because of it’s popularity with unsavory marketing people, spam filters have been introduced and this can lead to legitimate emails being marked as spam. You cannot guarantee email will get through, but here are some steps you can take to help avoid your marketing emails being marked as spam.

The right selection of words

Spam Filters check email content for certain words. Avoid the use of words for obvious things such as free, lottery and so forth. But just as importantly, fill your email with plenty of regular sentences with good grammar and spelling.

Pay attention to your formatting

Avoid the use of any more than 4 font types, colour or sizes. In fact, you might want to avoid all styling and just send plain text rather than html emails.

Unsubscribe and contact information

Include unsubscribe option as well as your organisations contact information (Phone, Fax, Address)

Reduce number of spaces in email subject

Be mindful of the email subject used. Basic rule is keep it short, simple and informative. Don’t use special characters such as percentage.

Relay mail through your ISP

If you have a dynamic IP address (most consumer grade connections), it is better to relay mail through your ISP’s mail server. But…

Limit the number of recipients

Many ISP’s have an ‘email rate limit’ in place which limits the amount of mail users can send over a period of time. This acts as an effective anti-spamming tool and powerful deterrent for spammers. Speak to your ISP to ask them if they have this in place. onCourse will always send emails one at a time (batching emails is a bad idea for spam filters), but as fast as it can which is usually several per second. Your ISP may decide that this is too fast and start blocking emails after the first batch. A “business grade” ISP will be better able to help you bypass any filter they have.

Test and learn

Each time you send a marketing email, note how many recipients you’ve sent it to. If you encounter any issues where your emails are marked as spam, you’ll have an idea of what is or isn’t within your ISP’s email rate limit. As a good starting point, read this list of rules which a very popular spam filter uses: http://spamassassin.apache.org/tests_3_3_x.html (note that negative scores in that list are an indication that the email is NOT spam).