On 2007-12-22 at 10:37 +0100, Leonardo Boselli wrote:
> Ok but what if my MTA has 4 address on 4 subnets from 3 different
> providers an use each one in turn ? (none of provider warrant a 100% up
> time, but just a nominal 98.5).
Each (IP, sender, recipient) triple is recorded, together with first
attempt time. 10 minutes after the first attempt, further attempts will
fail.
So you can rotate all you like; provided that you retry from the same IP
at least once, more than 10 minutes after the first attempt from that
IP, then it will go through.
You're free to run your mail-servers as you see fit, I'm free to run
mine as I see fit. Greylisting leaves a nasty taste in my mouth, but it
works and of the various approaches available, it's the "most
reasonable": someone sending mail to me must, the first time around, be
willing to hold onto that mail for a little while and retry; the cost is
borne appropriately, there is no financial blackmail and I don't expire
greylist items, so you remain a "good sender". For what it's worth, I
whitelist based upon presence in the
http://www.dnswl.org/ whitelist, so
that if your IP is listed there then I won't greylist.
If anyone has recommendations for suitably comprehensive whitelists
which permit rsync access, I'm willing to use more and also provide DNS
service for reasonably run whitelists.
-Phil
