Subdirs and nosubdirs Channel Options

Using multiple subdirectories to store queued messages
The MTA by default spreads all messages queued to a channel across 20 subdirectories. However, a channel which handles a large number of messages and tends to build up a large store of message files waiting for processing, e.g., a TCP/IP channel, may get better performance out of the file system if those message files are spread across even more subdirectories. The  channel option provides this capability: it accepts an integer argument which specifies the number of subdirectories across which to spread messages for the channel. The allowed range of integer values is 1 through 999. The default value is 20.

To disable the use of subdirectories for channel queues, use the  keyword.

See also:
 * File creation in the MTA queue area channel options
 * Channel options