Configure Email Router for Exchange Online
URL to use for outgoing profiles with the Email Router
I was setting up the Email Router (2015 on-premises) to send via Exchange in Office 365. I wasn't sure of the URL to use so I tried selecting Use Autodiscover which didn't work for me.
I found two articles that described the the URLs to use with different information. The articles
According to this article https://technet.microsoft.com/en-gb/library/dn768355.aspx I should use https://autodiscover-red001.mail.microsoftonline.com/ews/exchange.asmx (for the US data center). But I couldn’t get this to work.