This is more of a curiosity question than anything else. Has anyone ever received the max (10) diamonds and/or emeralds after voting? I think my max was 5 in diamonds and that was only once (then again, I haven't been on EMC for that long). The formula used cannot be a straight RAND(10). It must be weighted somehow. I'm not really looking to change the system and therefore this is not a suggestion. (Keep the formula the way it is. That way it makes voting worthwhile when you do get the max.)
I gotta say I don’t pay attention to what amount the diamonds and emeralds come in. I usually don’t collect mail after I hit a bonus. So I might have and I might not have hit those maxes. I just collect the mail whenever I feel like making time to collect it and store what I get in the appropriate spots. Edit: However I’ll test this out on my end and see what I get.
I opened a year's worth of unopened mail and recorded it last year. I just checked the video -- I didn't see 10 diamonds or 10 emeralds received at any point. Maybe it's extremely rare.