gnus-refer-article-method

gnus-refer-article-method is a variable defined in `gnus.el'.
Its value is

current

Documentation:
Preferred method for fetching an article by Message-ID.
The value of this variable must be a valid select method as discussed
in the documentation of `gnus-select-method'.

It can also be a list of select methods, as well as the special symbol
`current', which means to use the current select method. If it is a
list, Gnus will try all the methods in the list until it finds a match.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 24.1 of Emacs.