Synchronization problem

Dear Mailspring employees,

I have been using Mailspring for some time now. Unfortunately, this e-mail system has been failing daily for a few months now and I can’t answer e-mails (but they do come in) the error message is: that there are synchronization problems. After checking the setting several times, the problem persists, despite the connection being reported as successful, sometimes everything works as it should, but most of the time it doesn’t… and can’t answer and/or delete emails. The data is all set correctly and checked with my server. Unfortunately, if this error cannot be fixed I have to cancel my subscription. I would like to hear if there is a solution from your side.
Sincerely, Suzan