Have you been unable to verify account name or password on High Sierra, or changed your keychain password recently and then had issues with Apple mail and other services such as Linkedin, Google, Flickr, Vimeo? I have had exactly this situation and I solved it with a quick fix that will save you a lot of time. Read more about How to solve the Apple mail Unable to verify account name or password issue
Articles - Misc
Articles I have yet to pull into any particular category. When I do write it is usually because I have got a bit passionate about something and the list below are those articles.