Cannot delete smtp server in mail application on High Sierra I have removed an smtp server the way as specified by apple for the mail application on macOS. However the smtp server keeps reappearing. I have followed the suggestions in https://discussions.apple.com/thread/2775382?start=0&amp;tstart=0 but no luck.
Does anyone have any idea on how can I force delete the smtp server?

Thanks
I have found in Keychain two hidden entries that corresponded to smtp servers (com.apple.account.SMTP.asynchost), delete them and puff, no more ghost smtp server on the mail app.

Take caution as deleting those entry apparently can lead to keychain malfunction. Do backups of the keys before delete them.

See discussion here: https://discussions.apple.com/message/32426759#32426759