I'm sending an email to two persons with the same first name (Steve)
Greeting them by saying "Hi Steve, Steve" seems totally awkward. Is there a good way of writing this, besides leaving out their first names completely?
I think "Hi Steve and Steve" or even "Hi Steves" work fine.
If you know their last names, you could do something such as "Hi Steve G. and Steve A.," (assuming hypothetical last name initials).
It depends on the relationship you have with them. If they're close friends, you could say 'Hi, you two.'
There are several greetings that would work much better in this situation. "Gentlemen" or "Dear Gentlemen" are your best bets, as they work well in formal and casual situations. However, the answer truly depends on how well you are acquainted with the recipients; if you know them well, using "Gentlemen" may seem a bit awkward. "Hey guys" bears a more casual, friendly tone that might be better received by closer friends.
As you are on first names terms with both of them, Hi Steve and Steve should be perfect and should sound fine to the mail recipients as well.
Are these two Steves part of the same social group? Would many people know both of them? If so, my choice, in an informal context, would be Hello the Steves. Addressing the two of them together as The Steves would make less sense if they are not part of the same social grouping. Also, I wouldn't recommend it in a formal context.