[sizzle]

I use periods and they work fine like for [e-mail] or [e-mail] which surprisingly resolves to my main email and I’ll block spam from any sender spamming that period address. Anyone know why this works?

[purkka]

This is a Gmail-specific feature. I'd guess it's there for user convenience and some protection against typos (accidental or malicious).

https://support.google.com/mail/answer/7436150?hl=en