This works for some providers (Google) but definitely isn't universal - MS/Outlook doesn't support it for example

I literally setup an alias last week in O365 Outlook using the pattern [email protected]? I’ve been able to receive and send using the alias as well. Maybe this is a new feature/behavior?

I may have misunderstood the parent comment - with gmail, you can add dots anywhere in the mailbox and it all goes to the same place (standard gmail, not workspace)

e.g [email protected], [email protected] and [email protected] all are the same user and will go into their mailbox (which I have used to avoid the + stripping that some sites do)

[email protected] and [email protected] are two distinct users.

Obviously if you control the domain or use a provider who supports it you can add an alias with punctuation but then you might as well just use e.g [email protected] to track the email source.