Username and password are incorrect connecting to IMAP server on a iphone

When you try to connect to the Exchange Server, Exchange 2003, 2007 using iphone you receive an error message, indicating that your Username and password is incorrect, even though you know that you are typing the correct username and password to connect to the Exchange Server.

Solution:

For IMAP the Username must be in the format Domain\Username, make sure that you enter your username in the above format. And if your Email alias is different from your username then you need to enter your username as follows Domain\Username\Alias. See examples below:

1. In this case the Username is Asmith and the default email alias is allensmith@example.com
So in the iphone IMAP userid field you will put the username in the format
Example\asmith\allensmith

2. In this case the Username is Asmith and the default email alias is asmith@example.com
So in the iphone IMAP userid field you will put the username in the format
Example\Asmith

Please note that there are other requirements for IPHONE to connect to the IMAP server such as Port 143 should be open on your firewall and Port 993 must be open if you are using SSL, also IMAP must be enabled on the Exchange server and the User must be enabled for IMAP in the Active Directory Users and Computers

The above username format is not required for SMTP to work.