Hi all, Some info before starting:
a. There are two postfix instances on two different boxes. One (named Postfix-INT) has only 1 IP and the other (named Postfix-EXT) has 5 ips (to divide traffic among them by defining separate smtp services). All of the below stuff happens at postfix-INT. b For differentiating between internal and external mails, I use virtual alias maps to expand the addresses. For ex, for shadya...@mail.com, it expands to only shadyabhi:mail....@internal.storage.box. Then there is a line in transport_maps that says something like: internal.storage.box lmtp:[1.2.3.4]:20026 External mails don't undergo any address rewrites. So, mx lookup is done to deliver the mail. c. We add a custom header using a milter say X-Custom with possible values of header L1, L2 and L3. Problem: (All of this happens on Postfix-INT, i.e. first instance) 1. If header is L1 or L2, REJECT (done via milter_header_checks) 2. If internal domains *(even that have header L3)* 3. then deliver it to our storage servers *(through lmtp, as explained above, it's done via transport_maps) * 4. else if external domains 5. If the header value is C 6. deliver via postfix-INT (Because I don't care much about the IP bound in postfix-INT) 7. else 8. relay mails to Postfix-EXT. ( * record in transport_maps. Note that this comes after the lmtp delivery part and is the last entry there) Thoughts: - Line 1 is pretty easy to do. Did it via simple REJECT lines in milter_header_checks. - Line 2 I think that this might be possible using check_recipient_access under smtpd_recipient_restrictions. Is there a better way to do this? (The intent here is to filter internal/external mails via check_recipient_access and not transport_maps. ) - Line 4-8 If the mail is external mail, what's the way to decide the transport depending upon the milter_header L3 that was added. How to achieve this? -- Regards, Abhijeet Rastogi (shadyabhi) http://blog.abhijeetr.com
