EV11 ;IMAP/SMTP on iOS devices send all mail via SMTP

We have just noticed that when an iOS (iPhone 5, iPad, etc... iOS v7.1.3) is configured for both normal corporate email and EV11 IMAP/SMTP email that all emails are sent out using the SMTP connector, including normal corporate email.    The corporate account is set as the default account on the iThing.  We are currently testing Android devices, but I suspect this is a iThing problem.

1) has anyone else seen, or noticed this?

2)  Any suggestions on how to resolve?

TIA