<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>On 27 Jun 2007, at 03:12, Seamus Allan wrote:</div><div><br class="Apple-interchange-newline"><blockquote type="cite"> Gareth wrote: <blockquote cite="mid:1182844619.26893.2.camel@gblades-suse.linguaphone-intranet.co.uk" type="cite"> <pre wrap="">See
<a class="moz-txt-link-freetext" href="http://www.mailscanner.info/wiki/doku.php?id=documentation:configuration:mta:postfix:how_to:reject_non_existent_users">http://www.mailscanner.info/wiki/doku.php?id=documentation:configuration:mta:postfix:how_to:reject_non_existent_users</a>
Thats what I do and it works very well.
Just make sure Exchange is configured to reject mail to unknown
recipients. If you cant do that then there are other ways such as using
LDAP to regularly pull out a list of valid addresses from exchange,
On Mon, 2007-06-25 at 23:24, Jody Cleveland wrote:
</pre> <blockquote type="cite"> <pre wrap="">Hello,
I've got a RedHat 5 server with Postfix and MailScanner. This server checks
all incoming mail and then forwards it on to an Exchange server. I'm looking
for a way to verify recipients without touching active directory. Will
either of these work at all?
smtpd_recipient_restrictions = reject_unauth_destination
smtpd_recipient_restrictions = reject_unverified_recipient
- jody
</pre> </blockquote> <pre wrap=""><!----> </pre> </blockquote> I am curious about this; it seems to make very good sense to do this (and will in fact cut down the number of bounces created by my mail gateway MailScanner machine), but I wonder how much more work has to be done by Postfix to accomplish this. <br></blockquote><br></div><div>It's a lot less than trying to keep running the mail queue that's full of undeliverable bounce notifications. Reject unknown recipients at SMTP stage will mean that you don't have to use your bandwidth to download the full message, process it through MailScanner & SpamAssassin, deliver or attempt to deliver somewhere else, create the bounce notification and attempt to deliver this bounce using your bandwidth. If it's not deliverable then keep retrying for x number of days and re-examining the message in the queue to work out when it must keep trying.</div><div><br class="webkit-block-placeholder"></div><div>In comparison any form of db look up from hashed file to SQL or LDAP is really cheap. Couple that with one or two other tricks such at proxying for SQL for example (To retain connections) and you really have very little overhead at all. In fact there are other checks that are more work, such as RBL look ups that are much more work.</div><div><br class="webkit-block-placeholder"></div><div>Drew</div></body><br />--
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