Recently added two new domains into an Exchange 2010 SP3 server for a total of 3.
Each user has 3 different usernames and mailboxes.
15 Users, 12 Androids, 3 iPhones.
All androids connect to all 3 exchange accounts without issue and send/receive just fine.
The 3 iPhones ALL suffer from the same issue which is.
When adding ANY 1 of the 3 accounts, no problem.
When adding the 2nd account, they cannot and get the error that an identical exchange account already exists.
Found lots of post online talking about this issue being caused by 3 mailboxes with same user and pass, but this site has different usernames, and mailboxes.
Any help would be appreciated.