Email coexistence, with or without Coexistence Manage for Notes (CMN), can be configured within a single domain ("single namespace"), or you
can differentiate the two environments with different domains or subdomains—for example: domino.sitraka.com vs. exchg.sitraka.com. CMN’s Mail Connector integrates easily into either method.
NOTE: When coexisting with Office 365: Direct free-busy lookups from Office 365 to Notes are not possible with a single-namespace configuration, in either a hybrid or non-hybrid implementation, due to access/permission restrictions to the remote Microsoft servers. Bi-directional free/busy features with Office 365 can be configured only with routing domains (e.g., coexist.sitraka.com).
By the multi-domain/subdomain method, Domino and Exchange are assigned different subdomains to differentiate the two internally (within your network), so email can be routed between the two servers by SMTP
