I thank a lot alla people working on this project.
I'm really sorry because I don't know perl programming language, so to contribute in the solution for the problem I'm reporting.
I had a server security scan with a program named nessus and that tool demostrated that my server (on what I am using anomy sanitizer 1.54) is not protected against 1 kind of nessus mail test:
"Nessus antivirus test 4: broken MIME attachment (ISO encoding)"
This mail test consists in a mail message with an attachment called "eicar.com" wich simply was not recognized in the file extension test I do with my Anomy Sanitizer.
I can only think it's because the MIME was deliberately created in a bad way.
I hope this will be useful to someone.