I've seen this before on my app when I don't handle the connection isn't quite up yet.
Report the bug to the app's author.
Except for my wife's iPad all our computers are Win7, and we are on a wireless network. We all use Windows Live email to get to our Hotmail accounts.
Recently, when my wife opens Live Mail she gets a message
"Cannot Send Email"
"The user name or password for SMTP:*********@firstname.lastname@example.org" is incorrect.
(I used ******** as our Email name for privacy).
The only choice is OK which is what she selects.
This does not happen on any other computers, just her iPad.