fast_chemail crate is not maintained and is too restrictive: it does
not accept domains without a dot.
Also validate email even if it ends in "localhost" to make sure email
address does not contain control character that can be injected into
SMTP protocol, like "RCPT TO:foo\r\nQUIT\r\n@localhost".
fast_chemail
crate is not maintained and is too restrictive: it does not accept domains without a dot.Also validate email even if it ends in "localhost" to make sure email address does not contain control character that can be injected into SMTP protocol, like "RCPT TO:foo\r\nQUIT\r\n@localhost".