Hurricane MTA Server Queue Files

Hurricane MTA Server has individual queues for each account. The queue is comprised of files located at the account's data folder. The queue uses 10 top level folders, each with 10 sub-folders. Queue data is stored within this structure in proprietary binary files that have an .mbin extension. These files can hold multiple messages and grow up to 32mb in size. These files are not reused and are deleted once all messages in the file are processed.

If the store service is shut down, you may have an memdb.bin file in the account's data directory. This is a temporary file used to store queue index information. This file is created when the store service is stopped, and deleted once the store service is restarted.

If you think you are having problems with these files, you can issue the CLEAR QUEUE INDEX command from the MTA's console page. This command stops the store service and deletes the queue index file (memdb.bin) for the specified account number. When the store is started back up, it will rebuild the index by scanning each message file.

In addition to the above files, the account's data folder also contains a set of temporary files that are used to cache messages currently being processed. These files have a .tmp extension and will remain until the store service is shut down. These files are reused by the service for each new message and there could be up to one file per simultaneous active connection. If the system is shut down unexpectedly for any reason, the MTA will scan these files at startup and recover any messages that still need to be delivered.