Johan Andersson wrote:
MailingListe wrote:
Zitat von Johan Andersson <[EMAIL PROTECTED]>:
Hi,
We are thinking to implement some form of greylisting at one of our
sites and wonder which one of the many flavors out there
that this group have found reliable?
I know postfix has its builting one from a while back, but feel unsure
if it viable for our site... postgrey and gps seems they added
some features that mighe be usable for us... like automatic trunking of
the list
I just starting to read up on it so I feel very noobish at the moment :)
We have six MTA's that receive approx 1million emails a day (total) on
roundrobined addresses.
Be sure to use some form of automatic whitelisting for real MTAs as it
will be painful to purge the million triplets in the greylisting
database otherwise.
We use postgrey with a long initial delay and a very long purge delay
for automatic whitelisted MTAs, so most of our day-to-day contacts are
in the whitelist with no further delay and no additional triplets in
the greylisting database.
Regards
Andreas
Yes,
I have been thinking about this way as well, although, the discussion
around keeping a central database for all MTA's have me wondering...
In the protocol, when a host is asked to retry later... .i.e. gets the
"451 4.7.1 Please try again later" response...
Will it the retry go to the same host or do a new MX/DNS lookup to
resolve the mailaddress?
With six MTA's on roundrobin, if it does a new lookup it could be a long
time before it hits the same host again.
With a central DB this is solved, but then we got a SPOF instead... :-/
which must be handle by the GL software...
with local db's as seems to be the case with postgrey, it means all
senders must "whitelist themself" to each host?
/Johan A
A single database does not guarantee a SPOF.
You would have to set up replication.
