See Mail::Box::Locker
See SYNOPSIS in Mail::Box::Locker
The ::Multi
locker locks a folder in each way it can. This way, the
chance is highest that any other program will leave the folder alone
during our access to it.
NFS-lock and Flock are tried. More may be added when the ways to lock are extended. DotLock overlaps with NFS-lock, but NFS-lock is safer, so that version is preferred.
See DESCRIPTION in Mail::Box::Locker