Dkim on multiple domains as mailchimp does

Question

I actually have a server with a email marketing app just like mailchimp.

Each user have their own email added to my app. I want to send a email campaign with the clients email from my own server but signed with dkim email.

In mailchimp the only thing that you do is type your email on a field and the emails are sended signed.

Im using postfix as server email and php for app, any advice please?

Answer 1

You can use OpenDKIM and setup a milter config in postfix and that will send outgoing messages that are defined in the configuration.