Diagnose Advanced options what parameters can be set?

Does anyone know what parameters you can set in the Diagnostics loggins tab advanced options of the accounts menu? I did not found any references in the manual on line

These are advanced options to resolve specific issues.

What problem do you have, as it may be resolved some other way, which is preferable?

On an irrugulare basis the client gives an erro on the imap connection to the mailserver. It stops sending and recieving mail. A message apears that the account details are incorrect. When checking with the test function I can see it is ok and the testmail is visual in the webmail. When clearing al the errorlogs it sometimes start again recieving and sending mail but sometimes not. It is for sure a problem with the client. So I was wondering why are the advanced diagnostics not documented this could give us a more clear picture of what is wrong.