yes.
i have been using it since it was actually freeware.
now its a paid app, but even much better than before.
its now ultra fast, and very complete malware* definitions.
can just keep it in yr menu bar and run it every so often as i do, or, it can operate in the background as well.
a lot of malware
protection is actually malware in and of itself as far as i am concerned.
ClamAV is light, simple, just works, never gets in the way, doesn't slow yr machine down.
also, its not russian in any way.
people to whom you send email to expect you to do at least the above.
mac heads who are always on about "no virus" on macs miss the point - anyone who works for a living receives email originating from across all operating systems, all over the world, and all kinds of machines. its not an "if" situation. you are dangerous, and non-respectful of your working colleagues if you dont use something to filter it all out.
*edited, thanks.