According to statistics, 80% of all sent emails are spam. As a result, spam filters are becoming stricter and even legitimate emails can end up in spam. There are some steps you can take to ensure that all your emails are being delivered into the inbox. But firstly, let’s discuss what the spam filter is and how it works.
What is a spam filter?
Even 5 years ago, the idea of the spam filter was something new and its work wasn’t checked enough. The spam filter is like a searching system, that scans the emails. If some suspicious material is found, the email ends up in the junk.
How does the spam filter work?
The information that the filter looks for can be divided into three categories:
- Where the message came from:
Anti-spam organizations have created special network lists, which are called RBL's. Spam filter checks such lists for the IP, that the message was sent from. If the IP address matches one on the list, the spam score of the message increases.
- Who sent the message
Using email headers spam filters check if the email was sent by a spam engine or by a real sender. Every email has a unique ID, but when the spammers send mass emails, they all have the same ID.
- What the message looks like
Spam filter analyzes the body and the subject of the email. Strings, which can be identified as spam are 'viagra', 'buy now', 'lowest prices', 'click here', etc. Also, it looks for flashy HTML such as large fonts, blinking text, bright colours and so on. A lot of spam filters compare the whole text to the number of suspicious words. So, for example, if your email is long, it will not be identified as spam because of a few suspicious words.