If you want your recipients to answer your emails to another account than the one used to send your messages, you can easily set a different reply-to address in YAMM.
How to set a different reply-to email address?
Click on '+ Alias, filters, personalized attachments...':
Then specify another account in the 'Reply-to address' field:
Click 'Back', and 'Send Emails'.
Once your recipient gets your email, he will notice a different reply-to address from the sender's address:
Set multiple different reply-to email addresses
In most webmail clients, when you reply to someone, by default it only replies to the main sender (unless you change this is in your webmail settings).
So if you add cc recipients to your campaign, your main recipients might forget to reply to everybody.
To activate this option, add different email addresses in the 'Reply-to address' field separated with a comma and a space. You can for example add your own email address (which can be different or not), and the cc recipient account:
This way, when your recipient clicks 'Reply', he will reply to all the specified reply-to addresses: