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A friend asked me the following, but since my Postfix-fu has not been exercised for years, I thought I should turn to you:

Mail for the organization ( is handled by which runs postfix. There exists a second machine named which sends email to a number of people. is not using a smart host and is managing its own mail both incoming and outgoing. However whenever sends mail to, the sender gets re-written to by How can this be prevented?

I have the postconf output, but do not have permission to post it, so if you need the value of any variable, ask.

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up vote 1 down vote accepted

If I can't get the configuration I'm unable to help. The only thing I can do is to refer to the Address Rewriting Manual. If you don't find the answer there we need the configuration. Or you have to ask a specialist who signs a NDA with your "friend".

And when the mail is not rewritten by a rule then you can use any address as sender. Even It's the problem of email that you can use any address as a sender.

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Thank you for the link. Implying though that my "friend" is me was uncalled for. I am a Postmaster and live and die by sendmail. I have not run Postfix since its early alpha versions. Had this been a sendmail configuration problem, I would not have posted such a question here. – adamo Sep 25 '11 at 18:47
@adamo I started with sendmail in the late 90s and thought "why the hell do I have to compile my configuration?". Then tried to switch to Exim and thought "Why is this so complicated to configure 'just mail'?". And was very thankful after using Postfix for it's easy and secure setup. Now use it for more than ten years. – mailq Sep 25 '11 at 18:59
I am not a sendmail fanatic. It is just that with sendmail I can do anything that I imagine / need. I've written this on picking an MTA. – adamo Sep 25 '11 at 19:12

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