The logging files are somewhat complex; three critical factors are coordinated access, restricted file length, and restricted verbosity.
The length of a logging file can be limited to 25-block units. This is extremely important because files can grow very long over a period of time, especially if there are many long messages sent or very verbose logging.
Restricted verbosity using the logging level setting is a way of easily tuning the amount of text entered into the log. This is probably the one parameter you need to be most concerned about. When the logging level is set to highest verbosity (level=FTR), MMDF becomes noticeably slower and I/O bound. However, this level also shows what MMDF is doing, and helps you to discern the source of errors. When you are used to the log codes, setting the logging level down is highly recommended. The lowest log level is FAT, for fatal errors. TMP logs temporary errors. GEN logs errors and general information. FST logs errors, general and statistics information.
See the description of MCHANLOG in mmdftailor(F).
Every major entry will indicate the name of the message involved. Entries from submit will show ``lin'' if the submission is from a user on the local machine. In this case, the end of the entry will show the login name of the sender. If the entry is labeled ``rin,'' then the mail is being relayed. The channel name, source host, and sender address are shown. Within parentheses, the number of addressees and the byte-length of the message are listed.
Entries from deliver show final disposition of a message/addressee. These are indicated by ``end.'' Then, there is the destination channel and mailbox name. In brackets, the queue latency for the address is shown in hours, seconds, and minutes.