I noticed "<3" appears at the very end of the my stackoverflow notification emails (after the zip code). Is this problem related to gmail?
Stack Overflow loves you! <3
This is the actual code in the email:
<span title="because we care" style="color:maroon"><3</span>
So to answer your question, this is intentional and not a problem with GMail.
each email is baked with love!
StackOverflow loves you.
I feel so warm and fuzzy. I love you too, Stack Overflow! <3