LM

LM is an acronym that people may use in an office setting to confirm they mailed the letters. It has become an obscure acronym since most important correspondences now occur digitally.

Since most people use LM in an office setting (if at all), they often send it via email or the work instant messaging service. For example, your co-worker may message you to ask if you mailed the signed documents, and you might reply with, "Yep, LM." You might also email your boss and say, "I finished the task for the week. LM, too."