==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release):
- Deployed with iRedMail Easy or the downloadable installer?
- Linux/BSD distribution name and version:
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):
- Web server (Apache or Nginx):
- Manage mail accounts with iRedAdmin-Pro?
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

Right now, only 1 dkim assinged to the mail. I saw other mail server using two dkim keys on their, so I want to setup my mail server to do the same.

I want my mail when sent look like below:

Authentication-Results: mx.google.com;
       dkim=pass header.i=@support.digitalocean.com header.s=mandrill header.b=nCRsVtHW;
       dkim=pass header.i=@mandrillapp.com header.s=mandrill header.b="Ky/JEsn/";
       spf=pass (google.com: domain of bounce-md_30039865.5da8996e.v1-00d15204d92a4e088166d76dd101bbf7@mda.digitalocean.com designates 205.201.137.27 as permitted sender) smtp.mailfrom=bounce-md_30039865.5da8996e.v1-00d15204d92a4e088166d76dd101bbf7@mda.digitalocean.com;
       dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=support.digitalocean.com

My iRedmail info:
- Deployed with downloable installer on Ubuntu
- Using Amazon EC2 to host
- iRedMail latest version
- Store mail account on PGSQL
- Webserver Ngix
- Managment mail account with iRedMail normal