All Barracuda Spam Firewall 100s, firmware versions 184.108.40.206 and above.
The Barracuda Spam Firewall 100 enforces a limit of 50 users for spam and virus scanning.
To enforce this limit, administrators must explicitly enter the 50 users to scan for spam. If the users are not in this list, spam scanning will not be enabled.
This step is documented in step 5 of the Barracuda Spam Firewall - Quick Start Guide, found here:
It reads as follows.
MODEL 100 ONLY:
Go to the Users page and perform at least one of the following:
- Enter the email address(es) on which the Barracuda is to perform spam and virus scanning under User Configuration, one entry per line.
- To have email addresses automatically added to the Barracuda as mail arrives, make sure the Enable User Addition option is turned on. Note: If no users are specified and the Enable User Addition option is set to No, then no scanning of any incoming email will be performed.