How can I prevent an alias to be used when I reply to emails?
You can tell Missive to never automatically select a particular From address (known as an “alias”) when replying/composing a new email. You’ll still be able to manually set this alias in your From field if you need to.
To do this, open your Accounts settings, find the alias you don’t want to reply from, and check the option that says, “Never automatically select as the From address when composing an email”. Depending on whether you are the account owner, you may need to click Edit next to the alias to see the checkbox in question.
If you own the account:
If someone else owns the account and has shared it with you: