Companies often have a specific email setup where they have one central inbox with multiple aliases set up which can be emailed and replied and would like to reply as these aliases even from LiveAgent. This doesn't work out of the box in LiveAgent, but it can be quite easily achieved with a specific set up.
Let's say you have your Gmail / G Suite inbox as email@example.com and you have aliases firstname.lastname@example.org and email@example.com. In order to be able to receive and reply emails sent to all 3 addresses from the same address which was emailed by the customer you'd need to do these steps:
1. Log in to the Gmail at firstname.lastname@example.org, click the Gear icon ⚙ in upper right corner, then go to Settings and to the Accounts tab. Here under Send mail as: section you need to click Add another email address and add all your aliases (in our example both email@example.com and firstname.lastname@example.org) so you can use these to answer the received emails. Here is the Google's guide on how to do this.
2. Set up forwarding from all the accounts/aliases in Gmail/G Suite so that it forwards/resends all the incoming emails to the built in email address of your LiveAgent account. If your LiveAgent account is mydomain.ladesk.com, then the built in address is email@example.com but you can double check this under Configuration->Email->Mail accounts section of your LiveAgent admin panel.
3. Create all the aliases as Forwarding mail accounts in your LiveAgent. You'd go to Configuration->Email->Mail accounts->Add email account->Other->Forwarding. Here you'd enter each alias into the Email field and as Send type you'd select SMTP. As the SMTP details you need to use the SMTP details of your Gmail / G Suite inbox so in this case firstname.lastname@example.org. You'd use the same SMTP details for all the Forwarding accounts you create.
Once the accounts are correctly set up and connected LiveAgent will be able to reply the tickets/emails using the same email address from which it fetched the given email.