How to sort messages by date by reverse order, and unset expiry for all messages?

[Benjamin L. Russell]

Does anybody know a keyboard command and a configuration setting for
sorting messages by date in reverse order within a group?  There does
not seem to be documentation specific for this configuration option.

Also, does anybody know how to unset expiry for all messages within a
group?  I tried using the group configuration menu, but all the boxes
are marked black, and it is not immediatly clear how to ensure that when
I read a message, it still remains available, and is not marked for
expiry.  Although the boxes do get checkmarked when I click on them, I
am afraid if I don't change any settings, then if I read a message, it
will get marked for expiry and deleted a week later.

I would like to configure Gnus so that for all groups, no
messages are ever marked for expiry, but remain available to be read
even after being marked "read."  I.e., read messages should be marked
"read," but always remain available to be re-read (i.e., not disappear
from the summary buffer), and never be marked for expiry (i.e., never be
marked for deletion).

Any help would be appreciated.

-- Benjamin L. Russell
-- 
Benjamin L. Russell  /   DekuDekuplex at Yahoo dot com
http://dekudekuplex.wordpress.com/
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