Split Delivery: Hybrid Email Routing
Use more than one email system for a single domain.
What is Split Delivery?
Some mailboxes on the domain stay on another system (for example Microsoft 365) and the rest are hosted here. Mail that arrives for an address we do not host is passed on to the remote system you configure.
Example:
- executives@company.com stays on Microsoft 365
- staff@company.com is hosted on AtrioMail
Use Cases
- Cost optimization: keep premium licences only where they are needed
- Gradual migration: move users a few at a time
- Special requirements: different teams with different needs
How to Set Up
- Go to Split Delivery in the side menu
- Create a split delivery
- Select the domain
- Choose the remote system type and enter its hostname and port
- Save
DNS is still yours to set
Split delivery does not change your DNS for you. The domain's MX record decides which system receives the mail first, so plan the records before you switch:
- Point the MX where you want mail to arrive first, then let split delivery pass the rest on.
- Because mail is deliberately routed to more than one server, the DNS Checker in Tools reports the extra mail servers as something to review. That is expected for a split-delivery domain.
- Copy any record values you need from the domain's DNS Setup dialog in Email Domains.
Note: this is an advanced setup. Contact support through the live chat in the control panel before you switch a live domain, and we will go through the routing with you.