Re: sanesecurity signatures for clamav
And massively more complex to manage, with far more potential bugs, undocumented interrelationships and dependancies, too.
For a simple mail server for anything up to SMB, Exchange is huge, huge, overkill - and more expensive if you aren't on Technet.
The only people who should use Exchange are those who explicitly need it - for everyone else, there's Linux/Unix based tech.
Steven R