I joined a Lobsters thread about a researcher buying noreply.net and suddenly found myself in the middle of a flood of comments from other Sean Conners who also received each other’s mail. The thread showed that I’m not alone, yet it also revealed how many people still don’t grasp how email works.

The root of the problem is Gmail’s decision to ignore periods in the local part of addresses. Google claims it is to reduce confusion between [email protected] and [email protected], but the change also creates legacy issues for early adopters who signed up before the tweak. This has led to occasional mis‑routing of emails from banks, schools, and other services.

I’ve had this problem for about 10 years. By cross‑referencing my dry‑cleaner and car‑dealer records, I eventually traced the stray emails to a sender 3,000 miles away. Despite owning the account longer than others, Gmail’s handling of periods still forces me to avoid using it for anything confidential.

The RFC‑5321 spec states that the local‑part must be interpreted only by the host domain, but it doesn’t forbid ASCII characters beyond a limited set. The list of disallowed symbols—quotes, parentheses, commas, colons, semicolons, angle brackets, brackets, slashes, and the commercial at—remains largely ignored in practice, adding to the confusion.