Please refer to following PDF guide to setup Exchange 365:Anchor office office
...
Company MX should be configured as:
| Code Block |
|---|
10 |
...
postfix.server.acompany.com |
...
20 exchange365.your.exchange.mx.record.goes.here |
Note: For faultless function you must make sure that none of the Exchange connectors that are sending/receiving mails from/to the DMS have any size limitation imposed.