Issue with sending emails from MS Access via outlook

I have successfully set up a process within Access that allows me to send emails through Outlook however, I have several Gmail accounts withing the Outlook programme - for different roles I have. I want to be able to specify which account the emails go out through so I can control which email address is used for replies. I have tried changing the order and the default settings of the Outlook accounts within Outlook to place the one I want to use at the top, and also to set it as the default, but from within Access only one account (not the one I want to use) is ever used (ie emails lodged in the outbox) no matter what settings I change in Outlook. Can anyone help.