I’ve just upgraded from Mavericks to Sierra (after going Mavericks to High Sierra late last year and returning to Mavericks due to incompatibility with FCP7).
Everything seems to be working fairly well, except for Mail. All of my (working) settings have carried over from Mavericks, and yet my email accounts (“ncable”, aka iiNet) are offline, with the following error:
Trying to log in to this POP account failed. Verify that the username and password are correct.
I have tried changing the password in case it didn’t copy over correctly, but no good. Tried adjusting the port setting… but no go.
Is there some setting I’m missing, or a known issue with Sierra & Mail?