I sent the emails asking for the LOR back in September, almost 2 months before they would receive an email from the school inviting them to do it online.
It is true that my email address was unknown and it might've been considered spam. I sent the email again but that wouldn't have helped, in fact, I think that's more the reason why a filter would consider me spam.
One of the two professors is a big shot in a top college in London now, so I can see him clicking on ignore the minute he saw my heading. The other, is the sweetest person I've met so it surprised me from her. There's no way my emails didn't get to her since she works at the same school as the professor that did agree to do it so I'm sure their email server works the same and it did not send me to spam.
I went to a big state school but majored in philosophy so that department was small. All the majors knew each other and I had very close relationships with the small faculty department.
I would also like to think the best of people and like I said, I understand them not wanting to write the letter. A quick email telling me no would've been great. I can't be absolutely certain they, in fact, received the emails so I guess this will forever remain an unsolved mystery.