Mail help, please

[Stella]

A few months ago I was given a 21" iMac made, apparently, in 2010. After twenty years of being a PC user, I am now getting to grips, mostly, with the Mac and its software. Most of the time I like it, except for iTunes, which must surely have been written by the Devil himself .....

I had mail set up for my iCloud email, my gmail email and my own email via my internet provider, PlusNet. They are worked pretty well until I upgraded from Yosemite to El Capitan. The first two work, but my Plusnet email stopped working and gives me error messages. I have gone into the account to try to sort it out but it will still not work.

I thought I would just delete that account and start over again with it, but it is greyed out and I can neither delete it nor use it.

(I have Outlook on my MS Office subscription, but would prefer to have all my mail in one place.)

I'd be grateful if anyone could tell me why it failed under Capitan and even more so if you could tell how to delete the account so I can set it up again.

TIA

 

[honestone]

The initial version of El Capitan, 10.11, had issues with Apple's Mail Program. Version 10.11.1 was somewhat better in that regard, and 10.11.2 just recently came out. I don't use Apple'sMail software, so I cannot offer succinct advice about it. I do, though, use Outlook, and there have been a couple of new versions of Office 2011, most recently Version 14.5.9. It has always worked flawlessly with me. Also, my ISP is comcast.