I sent him birthday wishes, but instead of 'utmost regards', I wrote 'upmost regards'.
When someone corrected me AFTER the BBC6 already recieved my email, I wanted to die.
I DON'T WANT him to think that I'm a stupid American or something
So I forwarded back the message with my apologies and asked him to please excuse my grammatical error. In theory, 'upmost' and 'utmost' are synonymous, but I suppose 'utmost' is the most appropriate.