Description: A message loop is defined as a situation where the MTA decides that a given message will never be delivered to one or more recipients and instead will continue to loop endlessly through one or more MTAs. This variable counts the number of times the MTA has detected such a situation since MTA initialization. Note that the mechanism MTAs use to detect loops (e.g., trace field counting, count of references to this MTA in a trace field, examination of DNS or other directory information, etc.), the level at which loops are detected (e.g., per message, per recipient, per directory entry, etc.), and the handling of a loop once it is detected (e.g., looping

messages are held, looping messages are bounced or sent to the postmaster, messages that the MTA knows will loop won't be accepted, etc.) vary widely from one MTA to the next and cannot be inferred from this variable.