Dear @gemechis all depends on what do you want to achieve...
You can configure to block a mail domain, but as @PhoneBoy mentioned this wil only work if the mail arrives without TLS. You can configure to block a mail by IP-address, this will be blocked with TLS or without.
The content of a mail-message can't be checked if send via TLS, you have to decrypt these messages to do any content scan.
You can enable MTA and all features of "Configuring a Content Anti-Spam Policy", "Configuring an IP Reputation Policy", "Configuring a Block List" will work with TLS and without.
If you want to get the most valuable, you have to enable MTA, the Content Anti-Spam Policy, the IP Reputation Policy, the Block List and the ThreatExtraction features.