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Here is the problem: From any IP address not belonging to your mail server:

telnet 25  

mail from: <>
rcpt to: <>
This is spam.  Buy my stuff.

I'm using Postfix. I'm having a problem finding a solution to requiring SMTP-AUTH for email claiming to be from

Googling around, this guy has identified the same problem (where I cut-n-paste with some modifications) the above example from:

This link gets close to a solution but it has a side effect of requiring SMTP-AUTH for mail not from For mail not claiming to be from, I would do the usual RBL and Spam filtering.

In short, I want to reject mail to local domains ( from outside/unauthenticated clients claiming to be from local domains (

This is what I tried: I've tried both permit and reject as the default. Here is exact excerpt from my

smtpd_recipient_restrictions = reject_unauth_pipelining,
                           check_recipient_access pgsql:/etc/postfix/,
                           check_sender_access pgsql:/etc/postfix/,
                           (reject and permit both tried here)
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2 Answers 2

up vote 2 down vote accepted

I would try something like this:


smtpd_sender_restrictions =
    check_sender_access hash:/etc/postfix/access_table,

/etc/postfix/access_table:        REJECT You're not me!

The theory is this:

If they've authenticated already, they trigger the permit_sasl_authenticated rule and are allowed through. If they're not authenticated, it bumps along to the check_sender_access rule. If the sender domain matches "" the sender is rejected. (So unauthed + MAIL FROM "" = reject.) If it's any other domain, it continues on to the rest of your rules.

NOTE: This is untested. I would stick a warn_if_reject in front of that check_sender_access rule before trying it on a production system.

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makes sense! But you didn't try it? –  innaM Aug 6 '09 at 18:55
I've tried this - see the 2nd link I provided in my original question. The side effect of doing this is that mail from domains not claiming to be mydomain gets rejected also which I don't want to happen. –  Kilo Aug 6 '09 at 19:03
That depends on what you further tests you list after the check_sender_access test. If you look at the way I structured it, the default is permit. So if they're not SASL auth'd and they're not rejected by check_sender_access, the connection is allowed. –  Insyte Aug 6 '09 at 19:06
I updated my post to include what I tried. This gives 554 5.7.1 <>: Sender address rejected: Access denied With and without SMTP-AUTH. In my SQL table I have exactly as you have above. –  Kilo Aug 6 '09 at 21:30
I found the error in my ways. I was updating smtpd_recipient_restrictions instead of smtpd_sender_restrictions. Additionally, I had the order reversed between: check_sender_access hash:/etc/postfix/access_table, permit_sasl_authenticated when it should be as you've shown: permit_sasl_authenticated, check_sender_access hash:/etc/postfix/access_table Thanks for the help!!!! –  Kilo Aug 6 '09 at 21:44

On one server, where I have postfix with Dovecot with auth data in MySQL I did the following in

smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, reject
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