Type: string
Default: date-sent
When sorting by threads, this variable controls how threads are sorted in
relation to other threads, and how the branches of the thread trees are
sorted. This can be set to any value that
sort can,
except threads
(in that case, mutt will just use date-sent
). You
can also specify the last-
prefix in addition to the reverse-
prefix, but last-
must come after reverse-
. The last-
prefix
causes messages to be sorted against its siblings by which has the last
descendant, using the rest of sort_aux as an ordering. For instance,
set sort_aux=last-date-received
would mean that if a new message is
received in a thread, that thread becomes the last one displayed (or the
first, if you have set sort=reverse-threads
.)