Route emails with >X recipients through another interface/smarthost

[Johannes-TL]

Greetings,

I need to separate our regular mailings from our mass mailings. At the moment we are running a PoC with OpenEMM, so our mass mailings would be done through a newsletter system. As an alternative we could route all mails with more than a specified number of recipients through another interface (which would then use another IP), or through another smarthost, which would then also use another IP.

This is not the very best solution, but at least this would cause all L3 blocks to not work anymore (disclaimer: all our mails are perfectly legit) and would also solve approx. 70% of my issues. The rest could be mostly solved through other internal measures.

My question is - is this somewhow possible?

Regards
Johannes

 

[Stoiko Ivanov]

Not sure if I understand the question 100% correctly - but if you want to send out your newsletter through another path (i.e. public IP) - just create a cluster with 2 PMGs - that way the config can be shared between both - and you have a good overview what's going with both systems.

Why would this not work?

Alternatively - you can also just send out your newsletter without running them through PMG?

 

[Johannes-TL]

Sorry for beeing so inprecise with my explanation.

Basically I would need to route mails with more then X recipients through another external IP. PMG runs locally behind my firewall. So if I have an additional network interface on PMG with another IP, I could route all traffic vom IP 1 through IP 1 and all traffic through IP 2 through IP 2 (where e.g. IP 1 carries out all regular mail traffic and IP2 all our mass mailings). This wouldv eliminate the need for OpenEMM here.

Hope this makes it easier to understand

Regards
Johannes

 

[Stoiko Ivanov]

Basically I would need to route mails with more then X recipients through another external IP.

I'm not aware of such a feature in postfix (the MTA PMG uses) - and would doubt that it exists - number of recipients is nothing the MTA can know when receiving a mail - because the sending system can decide to split up the number of recipients in an arbitrary number of SMTP-transactions (e.g. each with 10 RCPT TO commands)

Do you send out your newsletter with your regular e-mail infrastructure (given that you speak of OpenEMM I thought that this is a dedicated system for sending your newsletters (and you could configure it to relay the mails through another gateway)?

 

[Johannes-TL]

Internally we run a linux mailserver, our users are sending the mails with bcc recipients. So it is technically speaking one mail with X BCC recipients that arrives on our mailserver. This one email is then sent to another mailserver as smarthost, that creates all the single emails. We did this to keep the interal mail queue as empty as possible, so nobody can delay internal communications with mass mailings. This smart host could be replaces with PMG, so this single mail with the BCC recipients would arrive there. So PMG would know about the number of recipients.

But if Postfix has no way of handling that I really have to technically seperate regular mails from mass mailings, which I thought I could circumvent (I am really not looking forward to implement that/train users/, ...)

 

[Stoiko Ivanov]

But if Postfix has no way of handling that I really have to technically seperate regular mails from mass mailings, which I thought I could circumvent (I am really not looking forward to implement that/train users/, ...)

As said - I'm not aware of any such functionality - but this does not mean that it does not exist - if you find anything related - please share it here
(it might help other users - and I could maybe give some tips)

 

[Johannes-TL]

Will do. But so far all my research and peers are sharing your answer.