With multiple email accounts, how do I select which one's Outbox I want to send from?

[AC Question]

I didn't even realize this was an issue until one email account - the one from which I was sending all my emails, apparently - was deactivated. Now I can't send any emails from my Android, because I don't know how to tell it to use one of my other accounts.

 

[hdickeychasins]

I was using 2 email apps - Gmail, with 2 different accounts, and a job-related app. It was the job-related app that closed, because we switched to a different email provider. So now I have 3 emails accounts on 2 apps: the 2 Gmail accounts, and a new app for work. I did some more self-testing, and I can respond to emails sent to any of these 3 email accounts; I only the have problem if I want to send an initial email from my phone (Motorola), because it's trying to send from the old work email system. Thanks in advance for any advice!