Whilst a iCloud account is my main mail I also have a Plusnet mail account which I have had a long time. All of a sudden it won't work. I decided to delete the account and set up again this time as IMAP rather than POP. PlusNet's instructions cover up to OS 10.7,a bit worrying. I could not get it to work and ended up sending Plusnet screen shots of settings and their latest suggestion has left me speechless - I will quote "If you are unable to get the client working with the details we have given I would recommend changing your email client, I do believe this would resolve the issue proving it is Mac Mail at fault."
Is anyone else using Plusnet and having problems?
Whoops, needless to say it was my error but not picked up by Plusnet to whom I had sent screenshots of settings. I had the mail server set to mail.plus.net whereas I should have changed it to imap.plus.net.
It's probably too late now but if it's suddenly wouldn't work as a POP account it may well be that their mail server is not quite talking the same language as Apple's Mail programme.
If in Mail preferences under the accounts section and then advanced you have the box ticked which says "Automatically detect and maintain account settings", you may find that Mail has ticked the box to use SSL all by itself! If you just manually untick this and then tick the box that says "allow insecure authentication", your email will work again but unless you stop it automatically detecting and maintaining account settings you will find SSL is ticked again in a couple of days!
David Moon 