[denton-scratch]

> It's not just gmail that does this, dots are almost always ignored before the @.

That's not my experience. Which non-gmail email software ignores dots before the @?

Thinking about this, I guess the sending MTA doesn't care about dots; it goes RCPT TO: <[e-mail]>. The receiving MTA then has to validate that address; it does that using some account database that isn't typically part of the MTA - it could be a unix account (no dots!), a database table, or an LDAP user. Finally it passes the mail off to a delivery agent, which hopefully relies on the same account database.

So the elision of dots appears to be a feature of certain account databases. So which account databases elide dots?

[account42]

MTAs can be configured to additional transforms before looking up the account. For example, postfix's virtual table [0] can be used for this and on my server it does elide dots in the local part (along with everything else).

[0] https://www.postfix.org/ADDRESS_REWRITING_README.html#virtua...