The most of the extensions are .eml.tmp, a few of them are .eml_tmp
Here's an example of one that is orphaned there as of this morning: 347233627713.eml.tmp
I went through all the SubSpool folders this morning, I have a total of 92 orphaned TMP files between all the folders. 87 of them are .eml.tmp and 5 of them are .eml_tmp
Still puzzles me why they are getting orphaned like that. I monitored one of the SubSpool folders and noticed that the .eml.tmp file would match a actual .eml file in the folder. So it's almost as if it's duplicated. They both have the same size and date/time stamp. So when the message is being received by the server, does it enter as a .eml.tmp file and then SM renames it to a .eml when it's fully received and ready for delivery?