Hello,
[sb_private_reply]We Really Apologize about the Delays in replying to your Support Query and Really Really Appreciate your Patience with us![/sb_private_reply]
This is Definitely Possible but will require some Additional Customized Code for handling this. We are using the File mechanism to check which Email was used to send the Last Message and then send the Message accordingly to the Alternate Email. Please download this File: https://www.dropbox.com/s/t9mi5s9c0vvegde/sendemail-alternate-emails.php?dl=1 and you can check the Code used for this. For this to work properly, please make sure that Writable Permissions are provided for the Folder where you save this File. Also, make sure that your Add your Emails in the File as mentioned.
This will definitely work fine. Thanks for your Patience.
Meanwhile, do let us know if we can help you with anything else or if you find any further issues with Canvas.