Mail not working

apple mail not working

My Apple Mail has stopped working. Initially, it might not send emails, now it doesn't even connect anymore and shows all accounts (2x Gmail, 1x iCloud) offline. Connection Manager spins for over 5min before finally saying all accounts are offline and therefore the only suggestion is to repair account settings in Preferences. However, once I open Preferences, there are not any t any Incoming/Outgoing settings fields, and if I open the 'Advanced' session or 'Edit SMTP settings' there are no servers listed. If I attempt to add one, it disappears as soon as I reserve it. There is no option anywhere to check/edit the Incoming server. All emails are fine from iPhone/webmail. I have been through all self-help from the past on the Apple website/this forum and a number of other blogs with no luck. I tried several times to delete/re-add the accounts again with no luck. If I attempt to add the accounts manually rather than using the Gmail set up in Apple Mail, it gets stuck on a spinning machine until I force close the app.