Send emails using custom sender address and not agent@vesonimos.com

When imosmail.exe is used in a Message Handler to send emails, agent@vesonimos.com is hardcoded as the sender email address. However, due to security restrictions in clients' servers, they should be using only internal domains (eg xyz@clientName.com) - meaning that at the moment they cannot send such emails.
Proposed solution would be a new configuration flag, whose value would be the desired email address to be used when sending emails via imosmail.exe.