What key would this progression be in?

Am C G E

I'm like 90% sure it's in the C major key, but the E major is throwing me off a bit '-' If it was in the key of C, wouldn't the E be a minor not a major?

Submitted January 27, 2021 at 03:42PM by TheTeacher000 https://www.reddit.com/r/Learnmusic/comments/l6bh6n/what_key_would_this_progression_be_in/?utm_source=ifttt