Unfortunately, Mailsite can't solve this. They come in from a valid address
and do HUNDREDS of queries for valid names on your server. Then they mail to
I wrote Sylvain at Vircom (VOPMail, uses the same engine that Mailsite does
and has improved it immensely www.vircom.com/vopmail) and he says the only
way to deal with this is to have a server timeout after a certain number of
invalid requests. None of the mail servers do that out of the box right now.
I would still encourage people to configure their smtp servers properly with
inverse addressing. I personally think this is the way to go.
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