1) I was try:
Setting -> Antivirus -> Scan And Risk->Protected Ports->Configure->add
Than I select SMTP in "Port Type" and type 465 in "Port"
I was than get the following message in Norton 360 Application:
"Add port to protect
This port is use by program other than the supported E-Mail program
It cannot be added to the list protected email ports.
2) Can Norton 365 scan for threat in IMAP protocol?
As you access your email, either through a web client or a local email client, other real time protection features of Norton will protect you against any malware.
As always, the first line of defence is safe web practices, such as not opening emails from unknown sources, and not clicking on links in emails.
Thank you Pemalink.
How about scaning IMAP protocol for threats
Norton does not offer scanning of encrypted email connections (SSL/TLS), so ports used for encrypted email are not supported (465, 587, 993, 995).