gnus-server-unopen-status

gnus-server-unopen-status is a variable defined in `gnus-int.el'.
Its value is

nil

Documentation:
The default status if the server is not able to open.
If the server is covered by Gnus agent, the possible values are
`denied', set the server denied; `offline', set the server offline;
nil, ask user. If the server is not covered by Gnus agent, set the
server denied.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 22.1 of Emacs.