After more then 10 years in business it starts to be really time to make RitLabs the Bat more stable.
When You close the bat it wants to sync imap folders or do maintenance on them. When there is a drop of internet connection or another error, there is no time out and the client does hang.
Every procedure should have a time out and a roll back. Additionally when the mail server timeouts or delivers error messages or simply block, in the logs it should be proper notified. At least 5 lines of logs should be permanently visible by standard so the user can find out issues.
Finally it is really time to step away from DBase related database format and switch to MySQL of PostgreSQL databases. There is no single reason not to use database abstraction.
Same with the codebase, it should be multiplatform. There is no linux client...