Hello there Mav-7,
Thanks for posting here on the Apple Support Communities! This is a place where other Apple users can submit questions or respond to others to help lend a hand. Let's take a closer look as we do our best to provide some additional insight.
We understand you're unable to send email from an Exchange account on this iPad. To get started, can you send and receive email with other accounts on the same iPad? If the issue is only isolated to the Exchange account, you'd want to follow these steps: If you can’t send email on your iPhone, iPad, or iPod touch
If you still have issues after completing all those steps, while other accounts work just fine, then you'll need to reach out to the Exchange account provider for additional help with troubleshooting your account.
We hope this helps get you pointed in the right direction.
Take care.