rsync /somedir work@backups::somearchive/ gets stuck in huge maildirs, rsync /somedir root@backups:/some/path/ works

[Matt McCutchen]

On line 735 of rsyncdaemon.strace.13682, the receiver is waiting for
more data to arrive from the sender.  Meanwhile, on line 1829 of
rsyncclient.strace, the outgoing buffer on the sender's socket has
filled up and the sender is waiting until there is room for more data
to be sent to the receiver.  Clearly the network is at fault for not
passing the data waiting in the sender's outgoing buffer on to the
receiver.

Matt