Re: Gnus: caching message headers?

[Gregory Heytings via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org>]

>
>> Is there a way to tell gnus-agent to create only a cache of headers, 
>> that is, to not store a local copy of the emails that have been read?
>
> Interesting.  IMO nowadays MUAs should work by systematically 
> maintaining a full local copy of your mailboxes/folders.
>

I (respectfully!) disagree.  This means that each MUA has to reinvent what 
already exists on the server, that is, to reinvent its own IMAP-like 
implementation, to store emails and to locate information in emails.  It 
is also a waste of resources, given that only a very small fraction of the 
emails are read more than once.  A "pure IMAP" MUA only has to query the 
server through the IMAP protocol, and only manages (1) a list of folders 
and (2) a list of email summaries in each folder.  In fact it could even 
manage nothing, and query the list of folders each time it is started, and 
create a summary of the N most recent emails each time a folder is opened.