The following commands can possibly help in investiagting various problems related to accounts on Sailfish OS.
From Sailfish OS version 4.0.1 onwards, the command below must be executed in the privileged mode.
For this, you will need to enable the developer mode.
1) List existing accounts and their account IDs
devel-su -p ag-tool list-accounts
The account IDs are the numerals 1,2,3,...
2) List all settings of an account (ID)
devel-su -p ag-tool list-settings <accountID>
3) Change authentication method
devel-su -p ag-tool update-service <account-ID> email int:imap4/authentication=1
The command above is an axample to change that authentication method setting to "1" which is "Login".
4) Delete an account (ID)
devel-su -p ag-tool delete-account <accountID>
5) Delete all accounts
devel-su -p ag-tool delete-account all