It appears that Michael Richardson <mcr+ietf@xxxxxxxxxxxx> said: >Keith Moore <moore@xxxxxxxxxxxxxxxxxxxx> wrote: > > But even though it's slightly cumbersome and a bit too expensive, > > anyone can get their own DNS name, point their MX records at a mail > > service provider of their choice, and change those MX records and > >No, that's not a portable (phone) email address. >That's a new phone number. Um, what? I'm using the same e-mail in the same domain I registered in 1993 wven though it's gone through a whole lot of different providers in the past two decades. Mail domains are extremely portable. On the other hand, to the limited extent we have portable phone numbers, it's because you need a government license to connect to the phone system and one of the conditions for that license is that you make your numbers portable. RFC 3482 explains number portability, which is similar to a DNS lookup of the dialled number before routing the call. Technically it would not be hard to add a per-mailbox DNS lookup to SMTP, ignoring the detail that no two mail systems agree what a mailbox is. (Are bobsmith and bob.smith the same mailbox? Are bob and bob+smith the same?) But unless you plan to license mail systems, there's no reason for any mail system to do it. Oh, and phone numbers aren't really portable. Even though the US and Canada have the same number formats and the same signalling underneath, if I want to port a US number to Canada or vice versa, too bad, can't do it. They're not *that* portable. R's, John PS: On the third hand, I can take my US mobile phone nearly anywhere in the world and it will work on the local network with my US number without problems, other than the ridiculous amount US carriers charge when you do that.
