> i've read the manual about and especially the part about
> content scanning but i don't understand if it is possible to
> do scans for viruses or with spamassassin if and only if a
> certain condition is met (e.g. a header set to a specific value).
> The short answer is: yes, it is - just put a condition in the acl.
As an example, you might decide only to spam check messages under a certain
size, so you could have: