1. If you mean that, for example, five people are offering a particular fandom + relationship (and aren't offering anything else), while only three people are asking for that, the three requests could just be matched to multiple offers and receive multiple gifts. It's called double-assigning someone, and it happens a lot. But many people offer multiple fandoms, just as they request multiple fandoms, so it's also usually possible to match them on a different offer/request.
2. When you sign up for an exchange, the mod can view the email associated with your AO3 account. I would contact you at that email.
no subject
1. If you mean that, for example, five people are offering a particular fandom + relationship (and aren't offering anything else), while only three people are asking for that, the three requests could just be matched to multiple offers and receive multiple gifts. It's called double-assigning someone, and it happens a lot. But many people offer multiple fandoms, just as they request multiple fandoms, so it's also usually possible to match them on a different offer/request.
2. When you sign up for an exchange, the mod can view the email associated with your AO3 account. I would contact you at that email.