Before sending a message it is important to check that the message is not seen as Spam by the ISPs.

By entering the page you can:

View test scores based on the SpamAssassin algorithm.
Run a Deliverability Test to perform a comprehensive test on a variety of spam filters. These tests can take a few minutes.

Here is an example of the SpamAssassin test:

The score reported in this section is 0.1 and is given by the sum of the values of the report that you see below. The higher this score, the higher the chances of this message being blocked or identified as spam.

The set limit threshold (default threshold of the main ISP spam verification tools) is 5. This means that if the message exceeds this limit, the providers using spam filters will most likely identify the message as spam.

Scores:
0.0 - 4.5 > nice and clean, no problems except those listed on the page. No action required.
4.6 - 7.0 > filters may reject the message. Clean up to fix the problem.
7.1 - 10.0 > you are entering dangerous territory. Fix the biggest and the smallest problems.
10.1 - 13.0 > almost certainly beyond the levels allowed by ISPs. A thorough analysis and cleaning is required.
13.1+ > severe problems. It needs a revision, systematic cleaning point by point, then carry out the test again.

Some recurring items in the report

0.6 HTML_IMAGE_RATIO_04 BODY: HTML has a low ratio of text to image area
It means that the image is too large in proportion to the text of the message. To cancel this score it will be necessary to insert textual parts to the message

1.1 URIBL_GREY Contains an URL listed in the URIBL greylist [URIs: domain.com]
To remove this score, any reference (in the message text, in the image host, or in the links) to this domain must be removed