outgoing mail server list empty
In Prefs->Accounts->Outgoing Mail Account, Mail's list of shows a list of servers previously used and technically still connected to the existing accounts.
However, by the time I click on the "Edit SMTP servers" item in the contextual menu, the new panel shows just one server.
I'm not sure since how long this is happening, but it's very frustrating as I can't change details for an account and I cannot deliver email anymore.
Attempted resolutions: I've tried to enable disable the iCloud email account and removed the plist file without success.
macOS Sierra (10.12.6), null