Outbound Email Routing and Inbound Email Restrictions are an Extended Service to route all outbound / inbound mail via a 3rd party SMTP relay server (i.e., a smarthost).
Outbound Email Routing routes all outgoing mail from your account via a 3rd party server based upon the sender's domain. Using a smarthost allows to create rules or policies for outbound Exchange email, perform content filtering, etc.
Delivery path for outbound mail is as follows:
Intermedia servers > the 3rd party server > the recipient server
Note: your smarthost needs to allow connections from all IP addresses used by Intermedia servers. When the Extended Service Request is submitted, Support will provide you with the IP range to whitelist. The full list of IP ranges can be found by looking up the value for the TXT record for spf.intermedia.net.
Inbound Email Restrictions rejects all incoming mail sent to your domain unless it comes from an allowed IP address. The MX records for your domain need to point to the 3rd party server.
The 3rd party server can be a mail-filtering solution, an archving or reporting solution, etc.
Delivery path for incoming mail is as follows:
the sending server > the 3rd party server > Intermedia servers
Note: we encourage you to notify Support of any changes to the IP ranges of your smarthost. If the IP range changes but it not added to the allow list on Intermedia side, this will cause delivery issues.