Do I need to buy licenses of any kind (devices, vm) to add an EM to an ML/EL that didn't ever have vmail?

I never have. The system just sees however many digital ports there are. 430s I think.

Thanks.

Remember to try to install it in slots 1-4 for best results.

I put one on the bench in a LW16 floppy system and it worked during testing.

Why 1-4?

In the Digital-Light bays, w/ LW 15/16, slots 1-4 were the "high-powered" slots because they were closer to the air vents / fans. I'm not sure that it makes that much difference in EL/ML architecture.

Still, if you have a slot available in 1-4, it's a good idea.

Mitel put out a tech bulletin recommending that you install it in the first 4 slots. I have found that getting in on the internal modem works better, less errors in getting data and programming.

Gotcha.

Had one in slot 6 and got all kinds of random errors.
Unable to access vm boxes, not a valid selection, not properly sending MWL. Moved it to slot 3 and problems went away.

Interesting... I think this has to go in 2nd cabinet, any flags there?