Sending E-Mail without source IP thru VPS
I have a high traffic website.
Due to DDoS protection measures I'm hiding the original server IP in every possible way.
For e-mail sending I'm using a HTTP passthru to a VPS: posting all mail data via curl to a VPS with open IP, and that was sending the mail, so the original server address is not seen).
This now prevents me to send a mass-mailing to all of my customer base, which is becoming bigger and bigger.
When I've tried to send a mass mailing, the VPS's apache halted with an 500 Error, waiting to be rebooted.
My question would be if there is any tutorial here to setup an SMTP server which does not show my server's original IP? I was trying out authmailer.com service, but that forwards the originating IP in a header field, which allowed my original server to be attacked via the IP
Thanks for the help in advance!