We’ve already explained how poor list control and the inclusion of certain words can affect deliverability rates in any email marketing campaign but there are other, more obscure causes of diversion to the spam folder. Reputation is critical as once you have been classed as spam, any slight warning sign will be given much more weight in a future campaign. 

The intricacies of spam filters are secret but we can decipher most current limitations from the evidence of what gets diverted. However once spammers exploit an opening it will be changed so diligence is never ending.

The fact that there is no charge for free email marketing templates should not concern you. They are an excellent method of not so much beating the filters as complying with their requirements. They like conformity to the norm but whilst there are limits, you still have the ability to be distinctive and noticeable by modification of the templates. 

One way of explaining how spam filters work is to see how they respond to the use of plain text as opposed to html in an email marketing campaign. If a filter discovers a suspect word in an html email then it will not automatically ban the whole email. It will assess the rest of it for concerns, such as proportion of text to image, number of links, call to action buttons, that sort of thing. If everything else seems OK it will probably let it through.

With plain text, there is little to go on. If the subject line gives rise to concern, then all that they can go by is reputation. Companies new to email marketing are not the only ones to be concerned. An established one which depends on plain text must take great care that it does not upset the filters as once reputation is lost; it is gone for a long time. 

There seems little doubt that the worst things that you can do is try and cheat the filters. They will be less concerned to find one of the difficult words in an email than if you try and disguise it by, for instance putting a space between each character. Be professional, open and aware.