It does sound like IMGate is great, but I don't want to learn
another OS and I love the flexibility if giving users the ability to
handle their own filters and quarantine with the Barracuda.
As I said, if you go Barracuda, you can go with a cheaper box and
cheaper subscription, saving yourself many $1000 over the years of
subscription.
IMGate/MX is best place for rejecting bad recipients (takes a huge
load off the BC AND the mailbox server, because BC queries the
mailbox server for every recipient, passing DoS and JoeJobs straight
through to the mailbox server. 100K bad recipients? BC send 50K
queries to Imail.)
IMGate accepts the exported list of recipients from the mailbox
server, rejects bad recipients, taking that load off BC and the Imail server.
IMGate Advanced now has weighted rejected at the envelope level
(before DATA command) so you can score based on
1. IP:
no PTR
PTR domain name regex matches for subscriber access networks, etc
RBL hits
1. helo:
no helo
illegal characters
non-fully-qualified,
not in DNS
regex string matches for subscriber access networks, etc
2. from:
null sender
regex string matching
And If things get really busy, I drop another one in and do some clustering.
I have scheme for load distribution where the load is split +/- 2%
between any number of boxes behind IMGate (eg, Barracuda or
Imail). The load distribution also works for spreading outbound load
over 2 or more gateways.
All of the above happens before DATA, so it's extremely efficient.
Then all the other features of IMGate advanced like sender
verification, greylisting, bad recipient rejection, great logging,
free anti-virus, etc.
Len
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