We have a PowerMTA server that receives incoming e-mail. Is it possible to forward specific domains to another existing SMTP server that's not running PowerMTA?
The solution that I found so far is to pipe the e-mails to mailx that's pointing to another SMTP server, but this looks hack-ish.
Thanks!
This is an example for routing gmail.com to SendGrid. You might need to uncomment use-unencrypted-plain-auth for some SMTP providers.
<domain gmail.com>
queue-to sendgrid.rollup
</domain>
<domain sendgrid.rollup>
# use-unencrypted-plain-auth yes
auth-username username
auth-password password
route smtp.sendgrid.net:587
use-starttls yes
require-starttls yes
</domain>
You might want to use virtual-mta and virtual-mta-pool if you are looking to use multiple SMTP providers to load balance outgoing emails. Let me know and I will update answer with its configuration.