Cannot disable PDF blocking in Zimbra7

[6233maxxer]

Hi.
I used to have an external spam check so I disabled AS and AV in my 7.2.7 install. Now I enabled in order to block js attachments, but even if the blocked extension list doesn't contain PDF zimbra DOES block these files with BANNED CONTENTS ALERT. I also checked and the Block encrypted archives option is disabled. I restarted the whole Zimbra twice, but the block still persists.

What could it be?
thanks

Example of blocked notification:
No viruses were found.

Banned name: .pdf,Documento_giustificativo.pdf
Content type: Banned
Internal reference code for the message is 02474-01/TcWYEfULs1j3


zimbra@webmail:~/conf$ zmprov gcf zimbraVirusBlockEncryptedArchive
zimbraVirusBlockEncryptedArchive: FALSE
zimbra@webmail:~/conf$ zmprov gs $(zmhostname) zimbraVirusBlockEncryptedArchive
# name webmail.domain.it