Authenticate with separate email accounts for correspondence and comment | MSMTP

How can I tell RT to authenticate with separate email accounts for the case of correspondence and comment?

We have been using MSMTP for outgoing emails in our RT 4.4.2 installation.
MSMTP has been configured to authenticate to a email account in local email server and then relay email. It was in my notice that RT simply modifies the return-path (From header) as per the addresses in the Queue correspondence and comment address options when sending out replies to tickets; and this wasn’t really an issue.
However, recently we are planning to move towards adding a security feature in the email servers such that it will reject / mark as harmful those emails whose return-path is not the same as the account it authenticated from. And this will start marking legitimate RT notifications as harmful.