fn bracketed_ip(received: &str) -> Option<IpAddr>Expand description
The address the receiving server saw, [203.0.113.7] or [IPv6:2001:db8::1],
in a Received header’s from clause: from helo (rdns [203.0.113.7]),
from rdns ([203.0.113.7]:5126 helo=x), or from [203.0.113.7] (helo=x)
when the address has no name. The first word is, with most servers, the
name the sender gave in HELO, which it may write [192.0.2.1], as it may
the helo= in the parentheses: neither counts while the server wrote the
address it saw.