However, there is no requirement to do so. Whitespace MUST not be used as a delimiter without another non-white delimiter also present, however older software may generate it. Delimiter Summary A summary of delmiters and the meaning they imply for the name on the right, or in addition, the name to the left. , Verified or generated identity. Name failed verification test. Name on left is FQDN of site that handles mail for injector.
Entry is unverified.
Identity on left is an old-style system not conformant with this specification. The colon is a valid delmiter for legacy systems, however, inside an IPv6 numeric address, surrounded in square brackets, it is a part of the path-identifier. Treat as part of identifiers. Suggested Verification Methods Sites attempting to verify an incoming entry should take the following approaches for common transports. They are not required, but not following them may lead to wasteful double-entry Path addtions.