A brand new account that I have no heard of, or spoken to (in or outside of guild wars 2), has send me 105g through in game mail with no message. Should i report said account, return the gold, take the gold + report, etc?
I would leave the Gold in the mail as is (not returned and not accepted), and immediately contact the Anet Support Team. If this other account was indeed being used to funnel RMT Gold, your account runs the risk for a perma ban. It will appear that you were the one who made the transaction, and that is not good.
Let Anet tell you what to do with the mail. If they tell you to delete it, do so. If they say keep it, then it’s ok to keep.
Yes, please DO contact Support! It would be a help to remove what appears from this info to be a gold delivery agent!
Mundo — I want to give you a big KUDOS for being so honest. I think a lot of folks would have seen that, thought “Windfall!” and not thought that maybe something was not-so-good with accepting it.
You’re a gem!
Please do not speculate, and post as “fact,” your theories about how things work. That’s really not fair to anyone! 
Suffice to say, we monitor what goes on in the game and take action on fraudulent and unacceptable activities, such as gold deliveries from an RMT. And occasionally — more rarely than the forums may lead you to believe
— a mistake is made. However, errors are quickly set right with a ticket to the team. After all, we want you to play the game and we want to correct any errors that we make!
But yes, you can trade and go about your business! And know that if something odd does happen, we have agents on duty, 24/7/365, and if that should happen, we’ll get things sorted ASAP!
