I remembered that the email associated with my username has my surname in it, and would rather this wasn't exposed. I assumed it would not be shown but have been seeing otherwise!
I purchased a game as a gift, selected their name, added a personal message and chose to send through their Steam Account in the options (not the send by email option). But they still receive an email with this option, I see. So will they see my email?
Best Answer
Yes, they will. Here's the (redacted) start of a recent gift email I got:
They'll see both your Steam name, and the email address Steam has for you. Note that this message will be sent whether they send the gift through Steam, or tell Steam to email it to you.
You can change the email address Steam has on file from
Steam -> Settings -> Account -> Change Contact Email...
. You can also avoid revealing your email address entirely by trading it to them directly with the in-chat trading system, although this requires you both to be online at the same time.