Clear emails reside on junk folder after applying deep inspection.

[Nemat]

Dears,

Yesterday we have applied deep inspection in our fortigate to inspect inbound emails (SMTPS/IMAPS/POP3S). Fortigate work find and discard all the emails that are infected, but we noticed some of the clear email recived on junck folder. 

Our mail server is Exchange 2016. 

1-Is there is anything we have to check it in fortigate?
2-Also if there is additional setup that we have to modified in Exchange server?

3-generlay does the encryption and decryption change email packets?

Thanks.

[Anthony_E]

Hello Nemat,

Thank you for using the Community Forum.

Could you please precise which version of FortiGate you are using please?

I will seek to get you an answer or help. We will reply to this thread with an update as soon as possible.

Regards,

[Nemat]

Dear Anthony,

I appricate your reply.

It's fortigate 1500D and the framework bulid number is 6.4.1.

Thanks.

[Anthony_E]

Hello Nemat,

It is a real pleasure to can help you :).

May I propose you first to download and install the latest FortiOS version 7 for your FortiGate-1500D and tell me if it is helping?

Here the link:

https://support.fortinet.com/Download/FirmwareImages.aspx

Thanks a lot in advance.

Regards.