On Mon, 13 Oct 2014 12:15:31 EDT erik quanstrom <quans...@quanstro.net> wrote: > On Sun Oct 12 14:37:47 EDT 2014, st...@quintile.net wrote: > > I am fairly sure the problem is to do with RAM size rather than the ras= > pberry pi per-se. > > 4000 messages takes up a lot of space - and upas stores messages in RAM= > . > > it's a little worse than this, actually. > > since upas stores messages in mbox format, the whole file needs to be rea= > d or written on > update. certainly one could optimize the read bit, but that would be dif= > ficult this means > that the the whole mbox gets written to the dump every day, and you need = > about 2x the > mailbox size ram for each upas/fs that is run. this does not work out we= > ll for large mm > messages, or small ram boxes like the pi. > > the solutions to this are straightforward > (1) store one message per file,
This is what MH (an old mail client) does by default. > (2) cache important data in an index to avoid opening all files, This is what dovecot (an imap/pop3 server) does. One other thing such mailservers do is to usually only *append* to an mbox file. Deleted messages are marked as such but their space is not reclaimed until you force a rebuild of the mbox file and its index. Pure imap clients typically only read last N messages from a given mailbox. More may be loaded as you scroll back.
