On 2/25/2015 4:53 PM, Research wrote: > Hello, > > I have recently begun deploying Postfix on a web server. > > Postfix is configured to handle the e-mail for the web server domain (i.e.: > receives e-mail for example.com), and then has virtual tables configured to > route that mail to Gmail accounts. I have mappings for all RFC required > e-mail addresses (i.e.: postmas...@example.com, ab...@example.com), and can > verify that mail sent to those addresses does go to the recipients on Gmail > successfully. I have also verified that I am not an open relay. > > In my syslog, I can see an e-mail transaction of the following form > (truncated): > > Feb 25 04:48:14 example postfix/qmgr[16092]: BBCE57FCD4: from=<>, > size=20118, nrcpt=1 (queue active)... > > In this case, a sender has attempted to deliver a message with no sender > (“from”), information. As far as I can tell, that is not-RFC compliant and > is most likely spam. > > Is there a way via: smtpd_sender_restrictions in main.cf that I can block > this behaviour, or is there another method of doing so ? > > Thank you. >
The null sender is used for RFC compliant bounces or non-delivery notices and MUST NOT be blocked. It's OK to block a particular message if the client or content violates some local policy of yours, but the null sender MUST NOT be used as blocking criteria. -- Noel Jones
