Using Antispam on local Network when Email Server is externally hosted with a Service Provider

[NMAICT]

Dear Colleagues,

Our Infrastructure currently utilizes fortigate 60F for network security. We keep receiving waves of phising email directed at individual staff and our general group emailing list. I have had to try antispam feauture of the fortigate 60F firewall to salvage the situation since the email service provider have not been responsive. Unfortunately with all efforts made we still keep getting these spam emails. Its show either i am not doing something right with configurations or its cannot be done unless from ISP side since email server hosted in their datacenter. Kindly advice.

Warmest Regards.

Ibrahim.

[Yurisk]

Hi, as you haven't shown what you already tried to configure, I can only reference some anti-spam config guides, like this one - https://community.fortinet.com/t5/Blogs/Anti-SPAM-Feature-on-FortiGate-Firewalls/ba-p/238369 

Before trying to config anti-spam, make sure you have the appropriate license for this. Also, be aware that with clients downloading/reading mails via POP3/IMAP protocols Fortigate cannot block spam, just tag as "spam" for endpoint mail clients to use such tag to filter out such messages. Also, using Proxy mode security policy for mail traffic is advised, as some features will not work otherwise. 

Additionally, if your email clients connect to the outside hosted mail server via SSL encrypted connection (most probably they do) SMTPS/POP3S/etc - only security rules with Deep SSL Inspection would be able to look into contents of the mail messages.