IMAP and Maildir

[sawyl]

While trying to fix my IMAP server - I eventually discovered that, following a software upgrade, I now need to specify MAILDIRPATH in the configuration file - I found the following gem from Dan Bernstein in the maildir man page:

Many sites use Sun's Network Failure System (NFS),
presumably because the operating system vendor does not
offer anything else. NFS exacerbates all of the above
problems. Some NFS implementations don't provide any
reliable locking mechanism.

He's pretty much hit the nail on the head - NFS is a failure. You'd think that in return for appalling performance, no locking, no cache coherence etc, you'd at least get a certain amount of reliability, but no, that sucks too.