I've installed GFI MailEssential antispam and now I need to configure it.
There is many options turned off by default.
In these cases, I'm not sure wheather leave them disabled or enable it:
Check if the email header contains an empty MIME FROM: field.
Check if the email header contains a malformed MIME FROM: field.
Check if the email headers contain different SMTP TO: and MIME TO: fields.
Verify if sender domain is valid (performs DNS lookup on MIME FROM:)
Can you please recommend?