> ------------------------------ > > Date: Tue, 02 Dec 2008 14:50:21 +0100 > From: mouss <[EMAIL PROTECTED]> > Subject: Re: Problems with backscaters and require authentication > > [EMAIL PROTECTED] a écrit : > > Hi, > > > > i have some problems with spammers and i would like to ask how to set > > postfix to validate sender email addresses only for our domains. Is > > there some way to do this? > > what do you mean exactly by "validate"? check that the address exists? > you can use reject_unlisted_sender. > > > > > Other thing that i want to ask. I have this problem: > > > > i connect thru telnet to the smtp server and send email this way: > > > > helo myhostname.example.com > > mail from:[EMAIL PROTECTED] > > rcpt to:[EMAIL PROTECTED] > > data > > something here > > . > > quit > > > > mydomain.com is domain from the system. > > > > i'm able to send spam to this user, using the same email address in > > "mail from" field. > > > > Is there some way to protect my mailserver from this kind of things for > > our domains. If "mail from" use our domains (for example > > [EMAIL PROTECTED]), then to require authentication. > > > > > smtpd_sender_login_maps = > hash:/etc/postfix/sender_login > > smtpd_sender_restrictions = > reject_sender_login_mismatch > > > http://www.postfix.org/postconf.5.html#smtpd_sender_login_maps > >
Hi, thanks for the reply. Yes i mean to check if sender exists, but only for our domains, not for all senders, because there are mail servers that reject this kind of checking. I suppose that when i configure this way my system, it will not make problems with rest of senders, right?
