Considered UNSOLICITED BULK EMAIL, apparently from you

Discussion in 'Server Operation' started by alextuturiga, Jun 16, 2010.

  1. alextuturiga

    alextuturiga New Member

    Hi,

    I have made my linux mail server from http://www.howtoforge.com/virtual_users_and_domains_with_postfix_debian_etch.

    Now I have a problem.
    Every day all the users receive an email like this:

    I have replaced my real domain with mydomain.com

    I don't know how to stop it.
    I've tried to send email from alex@mydomain.ro to alex@mydomain.ro without AUTH and it worked.
    How can I tel to postfix to require AUTH for all users, not only for the users that send email outside the domain?

    Thank you very much
     
  2. sjau

    sjau Local Meanie

    do you have a static IP address?
     
  3. alextuturiga

    alextuturiga New Member

    yes, i have a static IP address
     
  4. falko

    falko Super Moderator

    It seems as if spammers are using one of your addresses as the sender address for their spam. This is possible even if they don't use your server to send their spam, and there's nothing you can do about it.
     
  5. Mark_NL

    Mark_NL New Member

    I got these on our servers mostly when they send a mail to abc@abc.com and FROM abc@abc.com .. also idd what falko says is true .. i just let those mails discard.. since then no more backscatter mails :)

    /etc/amavis/20-debian_defaults:

    $final_spam_destiny = D_DISCARD; // (default: BOUNCE)
     
  6. alextuturiga

    alextuturiga New Member

    All the users receive this kind of email.
    how could a spammer know all the passwords?

    Like a sad before if a send an email inside the domain without auth it works.
    How can I configure postfix to request auth even in the same domain like it do when relays outside the domain?

    Thanks
     
  7. Mark_NL

    Mark_NL New Member

    They don't know your password ..

    i can fake it to .. i just send an email to user@domain.com with alextuturga@mydomain.com as FROM address .. simple .. no need to use any authentication then.
     
  8. alextuturiga

    alextuturiga New Member

    I thinks I don't understand what do you mean because if I try to send a mail outside mydomain.com I can't and nobody can without authentication.

    So sending an email to user@domain.com with alextuturga@mydomain.com as FROM address is not possible.

    What I don't understand also is why when I send an email inside the domain I don't need authentication and how can I do to request authentication.
     
  9. falko

    falko Super Moderator

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