My clients have been receiving a lot of email spam that have only images in them. No text.
How does one stop these types of email spam from getting though Email Security?
We have been seeing image-based spam attacks increasing in the last several months in fast-changing snowshoe spam campaigns. The best and most effective option is to get the examples of spam messages that you're seeing forwarded with the original headers to email@example.com or use the Spam Control for Outlook plugin to report these to Message Security for evaluation.
My client use the SpamControl plugin for all received spam messages. Isn't stopping the images from coming in.
I just sent 4 image based spam samples in to saas_spam email address.
These are very hard to stop, as many of the botnet/phishing domains used have published legitimate SPF/DKIM, imbed the graphic and word-salad the content. One of the first campaigns we saw come in, where from a Pan American netblock.