http://linuxexchange.org/questions/2763/postfix-sender-restriction-for-mynetworks-limited-domains-only<p>Hello! I use Postfix for SMTP. As a normal smtp server, my postfix receives mails from outside, if they are addressed to our existing mailboxes.</p> <p>In case of 'mynetworks' (legal internal) senders, it receives and forwards mails addressed to the whole world.</p> <p>For the latter, I'd like to restrict the sender domain for some valid domains only, like ...@mycompany.com, ...@myfriend.com The list of the valid sender domains is something like the unio of - mydestinations and - virtual_mailbox_domains</p> <p>Thank you for your efforts!</p>enTue, 20 Dec 2011 09:57:12 -0500http://linuxexchange.org/questions/2763/postfix-sender-restriction-for-mynetworks-limited-domains-only#2766<p>Ahhhhhh that's a horse of a different color then.</p>RonTue, 20 Dec 2011 09:57:12 -0500http://linuxexchange.org/questions/2763/postfix-sender-restriction-for-mynetworks-limited-domains-only#2766http://linuxexchange.org/questions/2763/postfix-sender-restriction-for-mynetworks-limited-domains-only/2765<p>Hi Ron, thank you for your idea. However, I prefer to be as simple as possible. And, in this case, the goal is mostly to avoid some unintentional fails of my collegaues. For example, to send out mails from the test system, the valid sender must be: testsupport@test.myproduction.com instead of support@myproduction.com and vica versa.</p>lexqltMon, 19 Dec 2011 17:23:45 -0500http://linuxexchange.org/questions/2763/postfix-sender-restriction-for-mynetworks-limited-domains-only/2765http://linuxexchange.org/questions/2763/postfix-sender-restriction-for-mynetworks-limited-domains-only/2764<p>I understand what you are trying to do - to make the mail system more secure, but return email addresses, domains, et al, can easily be spoofed. I'd suggest rather setting up Mail Assassin or Spam Assassin and utilize its' features instead since I think you'll be able to better control and secure your incoming emails that way versus the way you are trying to do it.</p>RonMon, 19 Dec 2011 17:09:28 -0500http://linuxexchange.org/questions/2763/postfix-sender-restriction-for-mynetworks-limited-domains-only/2764