iPost® SMTP Relay Service

How it works

Your computer systems generate and send an email message to an SMTP mail exchanger (MX) at iPost. Messages accepted by the iPost MX will be sent from your dedicated iMM sending IP addresses to their destination.

Additional details

For security, the SMTP Relay service is configured to only accept email from certain source IP(s) that you specify.

Outgoing messages will be sent from the IP address(es) assigned to your iMM client.

DKIM and DomainKeys message signing will be performed by iPost in the same way as for your iMM email.

SPF records will be provided in the same way as for your iMM email. If your relayed email uses a different From address than your iMM email, your are responsible for serving suitable SPF record(s).

Email bounce handling will not be provided by iPost. Bounces will be directed to the originating Envelope-From address.

Opt out suppression, reporting, iTL™ processing, inbound message filtering, and link tracking will not be performed on relayed email. If you wish to take advantage of these services, use the iPost Triggered Mailing API instead of the SMTP Relay service.


Contact iPost Sales at sales@ipost.com for current pricing information.