What are some alternatives?
When comparing amavisd-new and Scrollout F1, you can also consider the following products
MailScanner - MailScanner is a open source email security system design for Linux-based email gateways.
SpamAssassin - Use this program to "Unspam" your mailbox(es).
Proxmox Mail Gateway - Protect mail server against spam, viruses and malware with Proxmox Mail Gateway security for businesses, government, education and non-profit organizations.
Rspamd - Rspamd is an advanced spam filtering system that allows evaluation of messages by a number of rules...
Altospam - Antispam and antivirus software on Cloud
Akamai - Akamai is the leading content delivery network (CDN) services provider for media and software delivery, and cloud security solutions.