Problem:
iPhone user can't connect to Exchange 2013 via iOS Mail app
says "Unable to verify account information" on the phone.
Solution:
Reboot Phone
Delete Account for O365
Make sure the user is not using WIFI / Turn
off WIFI
Bring up Safari and connect to http://outlook.office365.com
Make sure you can logon with credentials
successfully.
Now set up the O365 Account in IOS
Email.
Server Account: outlook.office365.com
User:
email
You may have to uncheck SSL and then recheck
SSL
Now you should be
able to logon and start receiving emails.
Turn WIFI back on.