Sorting the Rmail File
======================
`M-x rmail-sort-by-date'
Sort messages of current Rmail file by date.
`M-x rmail-sort-by-subject'
Sort messages of current Rmail file by subject.
`M-x rmail-sort-by-author'
Sort messages of current Rmail file by author's name.
`M-x rmail-sort-by-recipient'
Sort messages of current Rmail file by recipient's names.
`M-x rmail-sort-by-correspondent'
Sort messages of current Rmail file by the name of the other
correspondent.
`M-x rmail-sort-by-lines'
Sort messages of current Rmail file by size (number of lines).
`M-x rmail-sort-by-keywords <RET> LABELS <RET>'
Sort messages of current Rmail file by labels. The argument
LABELS should be a comma-separated list of labels. The order of
these labels specifies the order of messages; messages with the
first label come first, messages with the second label come
second, and so on. Messages which have none of these labels come
last.
The Rmail sort commands perform a _stable sort_: if there is no
reason to prefer either one of two messages, their order remains
unchanged. You can use this to sort by more than one criterion. For
example, if you use `rmail-sort-by-date' and then
`rmail-sort-by-author', messages from the same author appear in order
by date.
With a numeric argument, all these commands reverse the order of
comparison. This means they sort messages from newest to oldest, from
biggest to smallest, or in reverse alphabetical order.