Greeting Monotone from Monotype.

Also available under a few other names:

Dekros (FontHaus, by Bill Wolfer)
Greetings (Rick Mueller)
Argonaut (clone of ? by SWFTE - has variants such as condensed, bold, extended, etc.)
Ganelon (Scriptorium - but upper case only)

- Herb

Looks like Dekros has an alternate M that fits the original invite perfectly, thanks a million Herb!

You're welcome - actually, they all have the alternate swash-M. Dekros has it in a keyboar-accessible position, the left brace. The Monotype font has it in the 'mu' position and Rick Mueller's Greetings has it in the currency position.

And just found one more - Grasshopper, by Nick Curtis.