gmail interested in zipfile content?

[bad_brain]

just tried to send a password protected .zip archive to a customer who is using gmail...and it was rejected:

host gmail-smtp-in.l.google.com[173.194.70.26] said:
552-5.7.0 Our system detected an illegal attachment on your message. Please
552-5.7.0 visit http://support.google.com/mail/bin/answ ... nswer=6590" onclick="window.open(this.href);return false; to
552 5.7.0 review our attachment guidelines. x43si20115322eep.40 - gsmtp (in
reply to end of DATA command)

makes you wonder a little....doesn't it?

[ayu]

hmmm, what happens if you remove the extension?
Does it look at the file header?

[bad_brain]

nope, they obviously look INSIDE the package, I have tried it with a .tar.gz file inside a .zip one: also rejected. the same .tar.gz file alone works. so they seem to have problems with opening archives inside of archives....and hey, when they already "look inside" it's a safe bet they also fetch and analyze the actual content to complete user profiles.

[pseudo_opcode]

yeah well dont ask how i know this.. but they have been known to detect custom written viruses inside zip files..

maybe they dont like nested zips... or anything other than your pdfs, docs, xls etc...

[bad_brain]

well, from their ToS they don't allow "password protected archives inside archives", but I also tried it with an unprotected ".tar.gz inside .zip" which was also rejected, and it just contained a sql dump so it couldn't be for malware issues.
but already their "no password proteced archives inside archives" is a joke, because it's not their business what people are sending (I know, asking for privacy on google services is SO naive ).