so @OP what do you have to say about Betcoin.ag claiming that you sent them emails from 2 separate accounts from the same email address, basing on their claims, it does seem like their accusation is real.
@Betcoin.ag if it doesn't breach any of your security(or something) would you mind sharing the evidence(the emails you mentioned) here? it would be nice to have evidence when claims like this are made.