gnus-registry-ignored-groups

gnus-registry-ignored-groups is a variable defined in `gnus.el'.
Its value is

(("delayed$" t)
 ("drafts$" t)
 ("queue$" t)
 ("INBOX$" t)
 ("^nnmairix:" t)
 ("^nnir:" t)
 ("archive" t))

Documentation:
*Groups in which the registry should be turned off.

You can customize this variable.