I also have this issue. When I send email from my iPad, using my work email account, (microsoft exchange), the send message is no longer being saved in the send folder on both iPad and laptop.
Emails sent from the iPad using the hotmail exchange account does not have this issue, a copy of the sent email is saved in the hotmail sent folder.
I discovered that copies of any emails sent from my IPad, using my work email (exchange), are all actually being saved in the hotmail sent folder.
I have already tried deleting all accounts and reconfiguring them on the iPad, this did not resolve issue.
Is there anyway of fixing this, so that sent messages are saved in the sent folder of the account being used and not the hotmail??
I have the same issue with mail written in reply to an Exchange email showing up in the sent folder of hotmail. I had this on both iphone and ipad.
However I am not even sure if the mails from the hotmail account are actually getting to the recipient. Annecdotal evidence points towards that they are not getting them.
I have not found a solution. The only way to mitigate this has been to delete native hotmail access and to access hotmail by web browser instead.