Disable submission on port 25

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Disable submission on port 25

Ben Lavender
Hello,

I’m looking to disable submission on port 25 and therefore have postfix
as a relay only server. Is this possible?


Thank you

Ben
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Re: Disable submission on port 25

Benny Pedersen-2
Ben Lavender skrev den 2018-03-03 23:31:

> I’m looking to disable submission on port 25 and therefore have
> postfix as a relay only server. Is this possible?

is sasl enabled in postconf -d ? :=)

if you keep it disabled in main.cf and only enable it in master.cf you
got it right

port 25 must not anounce AUTH in ehlo

but it should show STARTTLS

dissable STARTTLS will also disable AUTH

dissable STARTTLS will just be a fail
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Re: Disable submission on port 25

Wietse Venema
In reply to this post by Ben Lavender
Ben Lavender:
> Hello,
>
> I?m looking to disable submission on port 25 and therefore have postfix
> as a relay only server. Is this possible?

It used to be fairly common to put Postfix as a relay betweem
the Internet and a corporate network (read: Microsoft Exchange).

For the Postfix side see:
http:/www.postfix.org/STANDARD_CONFIGURATION_README.html
http:/www.postfix.org/ADDRESS_VERIFICATION_README.html

Without more info the quesion is difficult to answer.

        Wietse
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Re: Disable submission on port 25

@lbutlr
In reply to this post by Ben Lavender
On Mar 3, 2018, at 14:31, Ben Lavender <[hidden email]> wrote:
> I’m looking to disable submission on port 25 and therefore have postfix as a relay only server.

You SHOULD disable submission on port 25, but that doesn't mean you have to be a relay-only server. Put submission on port 587.

(Or disable submission entirely, of course)

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