[Dovecot] NFS issues

[Rick Romero]

>
>> It's possible that switching the Linux NFS server to a Netapp will help
>> (which is what it will be deployed onto eventually anyway)
>
> NetApp should help, but I doubt it'll remove all the problems. Also
> Dovecot's NFS workarounds work better for Linux NFS client than for
> FreeBSD..

I doubt this is related to the specific problem, but I've had issues  
with FreeBSD clients when using NFS over UDP.  You might try forcing  
tcp from them:
mount -o tcp host:/mount /mountpoint

Rick