Not sure if I have seen you on this site before, if it's your first time, welcome. If not, welcome back. my suggestion would be to simply call the property and asked to be transferred to wither of the two parties you want to converse with. I have not met the gm, but I did get some very good info for the concierge. I cannot remember his name, but he was a very nice gentlemen with a ton of knowledge about the area. he assisted my wife and I on information both local and day trips as well. By the way, I love this property and hope to get back soon. One word of caution, the valet rate is very expensive.
I have been able to google search for the name of the property, and general manager as a search subject and many times the email address, or at least a name, is easily found.
I did a quick search with your request, and it looks like the general manager at the Boston property is Victor Aragona. There was no email listed, but as the previous response suggested, just call the hotel and ask for Mr. Aragona's email address. You can also call Marriott customer service, and they should have the email, or call the hotel for you while you are on hold and obtain it for you.