Postfix Address Verification

Gareth list-mailscanner at
Wed Jun 27 17:50:15 IST 2007

Yes that will work on the condition that the exchange server itself rejects
mail to unknown recipients.
If the exchange server accepts all mail for its domain and then emails out a
non delivery mail for addresses that dont exist then it wont help you.

> -----Original Message-----
> From: mailscanner-bounces at
> [mailto:mailscanner-bounces at]On Behalf Of Jody
> Cleveland
> Sent: 27 June 2007 17:43
> To: MailScanner discussion <mailscanner at>
> Subject: Re: Postfix Address Verification
> On 6/26/07 2:57 AM, "Gareth" <list-mailscanner at> wrote:
> > See
> >
> ostfix:how_to:reject_non_existent_users
> 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,

So, just so I'm clear, (we're using Exchange 2003) it will work if I add
this (taken from the link you sent):

1) Confirm that contains the following line and add it if not:

verify unix - - n - 1 verify

2) Add the following to

In smtpd_recipient_restrictions add the following options:

reject_unknown_recipient_domain, reject_unverified_recipient

Then add the following options:

unverified_recipient_reject_code = 550
address_verify_map = btree:/etc/postfix/verify

3) Restart postfix and test functionality

The problem is, I need to be able to do this without using ldap, and I can't
change any settings on the exchange server itself. (it's under someone
else's control)

- jody

MailScanner mailing list
mailscanner at

Before posting, read

Support MailScanner development - buy the book off the website!

More information about the MailScanner mailing list