How to update mail groups only?

[Christopher Culver]

When I see the new mail notification in the Emacs mode line, I want to
be able to automatically update all the mail groups in Gnus, the same as
if I typed Alt+G manually for each mail group in the summary
buffer. Hitting G in the summary buffer is inconvenient, because it
updates all groups (including RSS feeds that are slow to download)
before it lets me get to my new mail.

Is there a way to update only mail groups?