Module addr_spec 

3.4.1. Addr-Spec Specification

Functions

domain

domain = dot-atom / domain-literal / obs-domain

domain_literal

domain-literal = CFWS “[” *(FWS dtext) FWS “]” CFWS

dtext

Printable US-ASCII characters not including “[”, “]”, or “".

local_part

local-part = dot-atom / quoted-string / obs-local-part