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Alnitak
Asked: 2013-06-11 05:35:43 +0800 CST

Postfix - accept all email to any user at any domain

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I need to configure an SMTP server to accept any email to any address that might happen to reach it on port 25 and deliver it to a local mailbox (i.e. a spam sinkhole)

The default supported MTA on my O/S is Postfix, of which I have no experience. I used to do a lot of Sendmail and Exim, but that was years ago.

Can this be done with Postfix?

postfix

3 Answers

  1. Best Answer

    You can do this using virtual mailboxes. Instead of the usual lookup maps, you'd have a PCRE table that looks like this:

    /.*/ spamuser

    to return the username spamuser regardless of what email address is the recipient.

    In your postfix.conf you'd have the line

    virtual_alias_maps = pcre:/etc/postfix/virtual

    There's more information about both virtual alias maps and PCRE tables at postfix.org

    • 11

  2. Here is how I done it

    create user webmail

    adduser webmail

    I had to install the postfix-pcre package. Code:

     sudo apt-get install postfix-pcre

    I created a file called /etc/postfix/virtual as follows:-

    Code:

    /.*/                        webmail

    edited /etc/postfix/main.cf to add this line:

    virtual_alias_maps = pcre:/etc/postfix/virtual

    For the absolute newbies (like me), if the configuration is correct, the query command: Code:

    postmap -q test@a pcre:/etc/postfix/virtual

    would return the email id specified in virtual file (/etc/postfix/virtual). In this case. Code:

    webmail

    To test the working, use the mail command from the terminal. Code:

    mail [email protected]

    enter the subject, mail body and press Ctrl+D (to exit the compose window).

    To view the message use the following command. (webmail is the mail id configured in virtual file. Substitute with your name.) Code:

    mail webmail

    PS:To check the mail log use the following command. Code:

    tail -f /var/log/mail.log
    • 6

  3. If you want to make postfix into an open proxy that will accept mail for any domain, you may want to look into this piece of code: http://www.postfix.org/smtp-sink.1.html

    It's basically a load tester (accept then discard), but you can also configure it to accept then store.

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