Are Some People Not Seeing My Emails? (Patreon)

This is mostly directed at $10 patrons, whom I always send greeting emails with about 24-48 hours after they sign up with my Patreon. Someone just signed up and told me they didn't see my email so now I'm wondering if there are other people who aren't getting the greeting emails? I also send emails out every few weeks to all patrons, so if you're a patron that's been around for a few months (or any $10 patron) and doesn't know what I'm talking about, let me know and I'll figure this out D: