I was reading through my ancient PMs to GregF, and my face was figuratively turning red as I noticed how obviously I was searching for the clearest, most congenial way to say "Hello, Greg" and "Thank you, goodbye" and never quite finding it, sounding more like I was supplicant to him for his almighty knowledge. Alright... I'll give you an example:

Title: A few things have been bugging me...
First off, I would like to thank you in advance for taking the time to read this. A lot of these questions have really been bugging me, so I would really, really appreciate it if you would answer them for me.

Granted, it gets a lot better after that, and that's really tame compared to other PMs I've encountered in which the asker is practically saying, "Please, almighty Greg the Sun-god, lend me the answers I seek. I'm deyeingg!1!! ='( "

In my experience, it is of no immediate consequence how you address Greg when you PM. For one, he never comments on it. But, of course, you should know that he is always happy to receive questions from fans -- you do not need to beg him -- particularly so when your questions are thoughtful, maybe clearly phrased, and have not been asked a million times (but 999,999 times is okay, lol).

Nowadays, I keep it simple. I usually ask one question that's on my mind, although of course there would be nothing wrong with asking more. Although Greg wades through a tide of PMs every day, it is a task he says he enjoys, but I recognize that it is one that no one would like to be bogged down by, so I eliminate the fluff out of my messages.

My typical message to Greg goes as follows. It's my generic template, and if you're unsettled about how you're currently messaging Greg, you can use it.

Title: [#] Question(s)
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Hello, Greg. I have [#] question(s).

[QUESTIONS]

Thank you for your time.