The following list provides details about additional queue features.
This release supports multiple queue directories. To use multiple queues, supply a –QueueDirectory option value in the configuration file that ends with an asterisk (*), as is shown in the following example.
O QueueDirectory=/var/spool/mqueue/q*
The option value, /var/spool/mqueue/q*, uses all of the directories (or symbolic links to directories) that begin with “q” as queue directories. Do not change the queue directory structure while sendmail is running. Queue runs create a separate process for running each queue unless the verbose flag (–v) is used on a nondaemon queue run. The new items are randomly assigned to a queue.
The new queue file-naming system uses file names that are guaranteed to be unique for 60 years. This system allows queue IDs to be assigned without complex file-system locking and simplifies the movement of queued items between queues.
Starting with version 8.12, only root can run the mail queue. For further details, refer to the changes that are described in the mailq(1) man page. For new task information, refer to Administering the Queue Directories (Task Map).
To accommodate envelope splitting, queue file names are now 15–characters long, rather than 14–characters long. File systems with a 14–character name limit are no longer supported.
For task information, refer to Administering the Queue Directories (Task Map).