Email Gateway - DLP Policy with Sophos list - is filtering quite all attachments, even xlsx and docx


it's been few weeks since our email gateway has changed behavior, and is filtering quite all attachments in the email.

with the DLP active with Sophos List, it starded filtering even doc, xls, docx and xlsx. i did some test using these files containing quite noting than a couple of words, but ethe email filter still remove them.

as I said, this has been happening for a few weeks, I described the problem to our Italian support, but after days of analysis they said that it is normal for the Sophos list to clean up these files, even if it didn't happen a few weeks ago!
it is a big problem because we can't change the sophos list with the customized one, because this list has never worked with us and even a Sophos sales engineer (pecialized in email gateway) that followed us some months ago has been capable to resolve the issue!
P.S: sophos also remove .p7m, wich are pdf signed and certified. i know that crt files are contained is sophos list, but seriusly, only in italian companies signed pdf files are used every day? why filter this kind of attachments? i really don't know what think about.