I have an Outlook.com account with a primary email alias as an @outlook.com address. I also have another alias address set up with the account with a custom domain. When accessing my email on www.outlook.com, I'm able to set it so that I can send an email from either address, and I can also set it to automatically reply 'from' whichever address an email is sent to. I'm struggling to find how to set up this option in Thunderbird. Could someone possibly point me in the right direction?