Sure, they save time by eliminating junk email.
But on the other hand, sometimes they also delete important messages.
Just imagine, how many deals aren't made, becuase you had sent someone an email and haven't received a reply.
Then you think: "hey, seems like he isn't interested in that deal" and you move on.
Both sites may be losing sometimes because spam filter deletes a "real" message. Even more when it comes to adult business, since we often yuse "suspicious" and "offensive" words in our correspondence.
