Funny, I just wanted to post an Ask HN to inquire how businesses deal with the increasing amount of spam. At my place of work, we currently get around 40 spam

Funny, I just wanted to post an Ask HN to inquire how businesses deal with the increasing amount of spam. At my place of work, we currently get around 40 spam messages per outwards-facing email. How do you deal with that? What software solutions exist to filter spam that work well with Microsoft Exchange?