Do you use more than one email address on your iPhone?
How to control which email is used by default
If you are like me and you use more than one email address on your iPhone you probably have one address you use more than the other(s).
To make life a little simpler you should set this as your default email address - here's how...
1 - Go to Settings
2 - Scroll down and tap Mail
3 - Scroll down to the bottom and tap Default Account
4 - Select the account you wish to make default.
That's it. From now on when you compose a fresh new email your default account will be used.
How do I send from an address that is not default?
1 - Tap Compose to begin a new email
2 - Tap Cc/Bcc, From:
3 - Tap From: address
4 - Scroll at the bottom to select which address you wish to send from
5 - Write your email as usual and then send