Flexibility in sending email address for "Key Tabs" in Manager

I am not sure if any one else has this pain point but would like to put it out there to invoke some level of thought.
Use Case:
We generate many quotes and Invoices which are in all cases emailed.
When the customer replies to quotes or Invoices the response will go to the Manager configured address.
This creates an overload for staff where the Sales guys do not want to be trawling account / invoice emails they are just interested in Quotes and Sales.
Likewise the accounts department do not wish to be bogged down with Sales / Quote responses.
Customers unfortunately do read content as to what email to reply to they just reply.
Also when POs are sent to suppliers their computer systems simply respond to Managers configured sending email address which amplifies the issue.

Could the idea be considered for Manager to allow at least two or more sending email accounts to be configured or for the different modules in Manager to have flexibility in sending email address? This will will give customers a sure fire email return path to the organisation and solve some internal pressures with volume. Please do not suggest email filtering.
Still wounded by Mutiny over Payslips I believe this thought will solve this issue completely too.

Could you not configure a rule in your email client to redirectect the incoming emails based on subject of email?

I know this is not a full avswer, but it seems unlikely that Manager’s email system will be adapted as you ask

Or send the emails externally to Manager?

Manager Server version is used. Mail filtering / rules are not a robust option in a multi user deployment.