Ignore specific subfolders within Maildir?

Consider Dovecot with "mail_location = maildir:~/.maildir".

Is it possible to configure Dovecot to completely ignore directories like ~/.maildir/.foo ? The subdirectory .foo is created by third party software and the name cannot be changed. Because of the leading dot, Dovecot interprets ~/.maildir/.foo as IMAP folder /foo by default, creates the typical subdirectory structure with cur/new/tmp, and exposes ~/.maildir/.foo to IMAP clients.

Not being able to change the name or location of .foo, I would like to tell Dovecot to ignore .foo's presence altogether. So far I have not found documentation about how that can be done (or if it can). Helpful pointers are appreciated.

-Ralph