Can I block malicious files sent via email ?

[Psrivastava]

If my organization users send or receive emails (internal or external) with malicious file attachments , will I be able to block such emails using PAN firewall file blocking features  ? I think Microsoft O365 already creates an encrypted channel so the email attachments or contents  are protected until the files are manually downloaded by user.

Will SSL decryption helps in this scenario ? 

[BPry · Accepted solution]

@Psrivastava,

Look at the WildFire verdict actions, specifically on SMTP. If you are using webmail then no, but if you see the actual SMTP traffic then maybe. 

The one thing to keep in mind here is that the attachments are usually randomized and therefore get sent to WildFire to recieve a verdict, and in that time it will be delievered so in most cases you won't have a chance to stop the message until it's already been delivered. You also have to ask yourself if you really want to risk false positives getting blocked by WildFire and your firewall, as there is no way to recover the message at that point, where on a mail filtering device you would have the abiliity to manually deliver said message.