Domain Sharing (Email Rewrite Services)
What is ERS or Domain Sharing?
Integration Pro adds the email rewriting feature to the already rich feature set of Integration. For mergers and acquisitions, email rewriting allows a company to present a unified email address to the outside world before and after the user’s mailbox has been migrated. Domain Sharing is a key requirement for any organization utilizing more than one Office 365 tenant to service their end-users.
For more information please read the Email Rewrite Service Whitepaper.
How do I enable my users for ERS?
Day 1 - ERS
To enable a user for Day 1 ERS, simply add them to the “BT-IntegrationPro-DayOne” group located in the source tenant. This is a cloud only group. The members of this group will be automatically replicated to their counterpart group in the target tenant.
If a user from a source domain has been added to the Email Rewriting Eligibility Group called BT-IntegrationPro-DayOne, their outbound email messages will be intercepted by the Power365 Address Rewrite Service (ERS). ERS will rewrite the message header with the target tenant’s SMTP Accepted Domain information. To the outside world, it looks as if the sender was already using a mailbox in the target tenant.
Day 2 - ERS
To enable a user for Day 2 ERS, simply add them to the “BT-IntegrationPro-DayTwo” group located in the source tenant. This is a cloud only group. The members of this group will be automatically replicated to their counterpart group in the target tenant.
If a Cutover (migrated) user is added to the “BT-IntegrationPro-DayTwo” group, any email sent from that user will appear as if they are still coming from the source mailbox’s primary SMTP address. During a merger or acquisition project, this allows a company to hide the migration process from the outside world, until all users have been migrated and the Accepted Domains can be migrated themselves.
How often does Power365 check the ERS groups for new members?
After adding a new member to ERS, it may take up to 15 mins to be fully enabled and ready.
After User Cutover do I need to update the Day 1 Group?
No, when a Mailbox User has been cutover and has been a member of the “BT-IntegrationPro-DayOne” group, do not remove that user from that 1 group after mailbox cutover. In an Premium Integration project type, when an external or internal source user replies to an old message with the original source email address, it will route into the source tenant for ultimate delivery over to the target tenant mailbox (before Domain Cutover). The membership of the “Day 1” group should remain populated with the cutover user even after mailbox cutover because it will need to be rewritten before routing to the target tenant mailbox. Otherwise, if not rewritten, any reply to that delivered message would contain the source address, rather than the new target address. This, in turn, could cause end-user frustration and confusion.
Does Power365 Email Rewrite Services (ERS) rewrite the address when a “Send-on-Behalf” delegate sends a message for an enabled ERS user’s mailbox?
Yes, Power365 ERS, sometimes called Domain Sharing supports rewriting the address of the mailbox owner and/or delegate. If ERS is enabled for both, both addresses are rewritten. If ERS is enabled for the mailbox owner, then only their address will be rewritten.
Does Power365 Email Rewrite Services (ERS) rewrite all the addresses when the sender adds other ERS enabled users to the To, CC or BCC fields?
Yes, Power365 ERS, unifies your external brand by rewriting the addresses of ERS enabled users. If ERS is enabled for a user, it will be rewritten regardless of the user that composed the message.