On 9/21/21 11:03 AM, Bill Cole wrote:
Empirical evidence. The use of a non-public address in a Message-ID correlates to a message being spam. In my experience, so does using an IP literal of any sort in a Message-ID, but that may be an idiosyncrasy in my mail.
Fair enough. To each their own.
Private IP addresses in general cannot specify globally unique devices (consider 127.0.0.1 or the very-popular 192.168.1.1) ...
Agreed. However, I don't think the non-uniqueness of the IP address actually matters.
... therefore a Message-ID using an IP literal as the RHS part with a non-public IP cannot assure uniqueness.
The use of a domain name or IP literal is RECOMMENDED, not even a SHOULD, much less MUST.
The thing that MUST be the case is that the message ID is unique. So to me, it doesn't matter if multiple servers use the same IP literal (or domain name) as long as the entire message ID is universally / globally unique.
I am still not seeing anything beyond RECOMMENDED that states that the RHS of a message ID needs to have any form of uniqueness. Hence why I think it's okay for multiple systems to have the same RHS.
Aside: I agree that the RHS ideally is universally / globally unique to separate divide the message ID space such that it's per sending system.
I simply don't see any requirement for the RHS of the message ID to be unique. In fact I only see a requirement for the message ID in it's entirety to be unique.
I guess this is a "spirit of the RFC" (RHS = unique) vs "letter of the RFC" (LHS + RHS = unique) type thing.
What am I missing? -- Grant. . . . unix || die
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