Group Agent Commands (Gnus Manual)

J u ¶: Fetch all eligible articles in the current group (gnus-agent-fetch-groups).
J c ¶: Enter the Agent category buffer (gnus-enter-category-buffer).
J s ¶: Fetch all eligible articles in all groups (gnus-agent-fetch-session).
J S ¶: Send all sendable messages in the queue group (gnus-group-send-queue). See Drafts.
J a ¶: Add the current group to an Agent category (gnus-agent-add-group). This command understands the process/prefix convention (see Process/Prefix).
J r ¶: Remove the current group from its category, if any (gnus-agent-remove-group). This command understands the process/prefix convention (see Process/Prefix).
J Y ¶: Synchronize flags changed while unplugged with remote server, if any.