I recently centralised all of my email accounts into a single Gmail account (handling three different domains) and wanted to use Mac Mail to access the account. While I’m not averse to having email from three different domains arrive in a single Inbox, I need to send mail from those three domains separately.

There’s no obvious way to add multiple email addresses to a single account in Mac Mail, but with a little searching I found a simple solution: separate the email addresses with commas in the Account Preferences:

And when you’re writing a new email, you can select the account to send from as normal: