Use EOP in Hybrid for incoming and outgoing mailflow

Hi Mark,

To archive the mail flow that you want you need to do the following in this order:

• Change TTL of MX record to 300 sec or 5 min;
• Review your SPF record to have your ip's addresses and Office 365 protection.outlook.com;
• Re-run Hybrid Configuration Wizzard to change the mail flow from centralized transport to users on Office 365 send directly from Office 365;
• Test Mail Flow;
• Change your Send Connector on Your Exchange Server to send directly to Internet;
• Test Mail Flow;
• Change MX record to Office 365;
• Test Mail Flow;
• Change the TTL of MX record to 60 min or 3600 sec

Note: You cannot use the EOP to send mails from your on-premises organization is not supported.