Multiple SMTP settings for different mailing segments

I got to know that this community (especially the project’s Lead) threats people who propose/find bugs/ want to mangle with anything as Enemies, or if you are a business they would ask EUR/an hour.

Thus you are better off with simply giving a go to:
http://jmaimon.com/sendmail/anfi.homeunix.net/sendmail/smarttab.html

https://www.cyberciti.biz/faq/how-to-configure-postfix-relayhost-smarthost-to-send-email-using-an-external-smptd/

if you are on Postfix simply add a line to your main configuration file
sender_dependent_relayhost_maps = hash:/etc/postfix/transport
and then, in that file
@centos.org.pl poczta.centos.com.pl

  • add as many relaying/routing based on source email address as you wish.

For postfix also: