El Capitan Mail send error
Updated to El Capitan and Mail produces an error when sending e-mail:
Error Message: "This message could not be sent because your account does not have a preferred outgoing mail server. Select an outgoing mail server from the list below."
I re-entered the SMTP for outgoing and the error message has stopped but the outgoing mail fails and remains in the Outbox. Receiving e-mail okay.
Does anyone have a solution?
MacBook Air, OS X El Capitan (10.11)