Hacker News Reader

> providers/servers should ignore everything from the + to the @

Why? I'm not sure it has ever been a standard and it's certainly not a default implementation for most providers?

A quick google search returns https://www.cs.rutgers.edu/~watrous/plus-signs-in-email-addr... . Although not standard, its use is "legal"

There is a standard, RFC 5233 on subaddressing: https://tools.ietf.org/html/rfc5233

Adoption is a mixed bag.