Q: How do I list email alias on iPhone?

Hey there schoodle! 

From your post, it looks like you have an email alias that you want as an option when sending/receiving message in the Mail app. With an iCloud email alias, that is something that can be done by tapping the Cc/Bcc line in any email you compose, as long as your iCloud mail is on. 

See: Using your @icloud.com email address - Apple Support

Send email from your @icloud.com address

Open Mail and start a new email:

• If you only have an @icloud.com address and don't have any iCloud email aliases, it will appear in the Cc/Bcc, From field on your iOS device or the From field on your Mac and iCloud.com. 
• If you have multiple email addresses, you might need to select your @icloud.com address: 
   
  • iOS: Tap Cc/Bcc, From, tap From, then choose your @icloud.com address.
   
  • OS X: Choose your @icloud.com address from the From menu.
   
  • iCloud.com: Click CC/Bcc From, then choose your @icloud.com address from the From menu.

Then complete your email and send it.

And then you can setup as the default iCloud account for sending as well: 

Make an @icloud.com address your default sending and receiving address

To make your @icloud.com address the default for sending and receiving email from iCloud, follow the steps below for each of your devices.

iPhone, iPad, or iPod touch

1. Go to Settings > iCloud. In iOS 7 or earlier, tap Settings > iCloud > Account. 
2. Tap Mail under Advanced.
3. Under iCloud Account Information, tap your email address. 
4. Tap the @icloud.com email address that you want to use as the default for sending mail from iCloud Mail.

 

 Cheers!