Can i send an email from me.com with an email using a different domain?
On a Mac, in the reply message, notice that the From: line has the down-pointing triangle that indicates that it's a menu. Clicking on it reveals a menu of all the email addresses you have configured. Select the one you want. The response will be sent through the SMTP server you have associated with the account corresponding to that email address.

On the iPhone, the reply message has a consolidated Cc/Bcc/From: field. (You have to swipe down to see it, because it's originally scrolled off the top.) Tap on that to expand it into separate CC, BCC, and From fields. Tap on the From: field, and note that a scrolling list appears at the bottom of the screen, with all your email addresses the iPhone knows about. Select the one you want to use.