When replying or forwarding outlook switches to another account?

[Arfur]

New mail goes via my default email account = OK. When replying and forwarding
a message, outlook switches accounts. I want the account a message came in on
to be the one used to reply or forward from.

 

[Sanjay Singh]

That is the standard behaviour of accounts i.e. the account used to reply
will be the same one that the e-mail was received on.

You may also want to have a look at SendAccount 4Outlook.
http://www.addins4outlook.com/sendaccount/

A common problem with using multiple accounts is accidentally sending out an
e-mail using the wrong account e.g. sending a business-mail using your
personal e-mail account.

Send Account lets you set a preferred account for each person you write to.

It warns if you if you try and send an e-mail to someone using the wrong
account.