I have multiple e-mail addresses associated with My Contact on my iPhone (6S, iOS 10.0.2). Some of those e-mail addresses are for accounts on the phone and some are for accounts not on the phone.
If I set the default mail account in iOS using
Settings->Mail->Default Account, this does not directly control the
From address selection of the outgoing mail. Probably this makes sense, because the
From address can be set independently of the account used to send. Most advice I find in other questions/Web search only centres on this setting, which doesn't appear to be the only thing which is relevant.
When I compose a new e-mail, the selected
From address is by default one which is a) not for the default account in Settings; b) not even an account which is setup on the phone. This is very undesirable.
As I enter the recipient name, the
From address sometimes changes. It can change to at least 3 other values (all from My Contact, all from accounts on the phone). This could possibly be learning behaviour based on previously sent e-mails. These choices are often not ideal but better than the default choice.
How is the
From address selection controlled? Can I at least control the default, even if the "intelligent" behaviour cannot be controlled? The default is almost always a poor choice for me, and I have to remember to manually check the choice and switch it every time.