After open a folder with IMAP server, do I need to close the connection/store before I open another folder? After I open a few folders, the connection/user pool of the IMAP server is full and all request was rejected by the IMAP server.

Dieter Wimberger

Basically you do not need to close a connection/store before you open another folder, but there are certain constraints that come from the provider implementation you are using.

In general taking care about resources is not a bad idea, open folders just when you need them (with the right mode), and close them whenever you don't need them any longer.

Especially when writing, because most likely implementations allow multiple readers, but only one writer.