There are 2 types of emails to be sent from my server: promotional emails to potential clients and opt-in emails to members of my site.
I want these two types to be sent from two different ip of same postfix server.

I want to ask, is that if my Postfix is set up in this way, even some of potential clients marked my promotional emails as SPAM, I still have opt-in emails to members of my site being unaffected?

Also, is it a good method to increase deliverability rate?

thanks.

What logic do you have to identify a difference between these types of email? different destination domains for example? Without knowing what data you can and can't use to distinguish, there's no chance of saying how to do this.

http://www.postfix.org/postconf.5.ht...relayhost_maps might give you angle to say that traffic from user a goes to smartrelay 1, traffic from user b goes to smartrelay 2, and then use some form of natting in iptables to nat traffic within the box based on where it's going... I'm unaware of being able to choose your IP address dynamically within a single postfix instance. You could always run two separate instances though I guess.

I really can't see a logic in wanting to do any of this though... why does it matter?

sorry i think i didn't make it very clear. I changed the names of the 2 types of emails to "non-opt-in promotional emails" and "opt-in members' email", does it seems more logical now?

thanks for your information about the sender dependent relayhost, i'll surely take a look, it seems i little bit difficult. do you know any tutorials that i can follow?

no that's no more logical in the slightest, merely confirmed you're spamming people. Why would the source IP address ever matter??

yes, my non-opt-in promotional emails may be regarded as spam,

i'm just thinking, let this 'SPAM' labelled to just 1 IP only, so that I can still send opt-in email using another IP,

That's why I want to use 2 IPs to send two different kinds of email. am I wrong at anything? I haven't done this before so please correct me if.

Not sending spam would be a good way not to be listed as a spam blacklist... but as above, probably just run two different instances and it'll be the easiest really.

thanks