Re: [EAI] The value of simplified downgrade

[Ernie Dainow <[e-mail]>]

SM wrote:
> Hi Ernie,
> At 06:57 10-09-2009, Ernie Dainow wrote:
>> Have alternate addresses stored on the server, associated with the 
>> primary EAI address for the account (this has been recommended in 
>> draft-yao-eai-deployment, section 3). Then add a new SMTP command, 
>> something like VRFY, that verifies an email address and returns the 
>> associated alternate address. So when an MTA discovers it needs to 
>> downgrade, it can use this SMTP command to get the alternate 
>> addresses needed from an authoritative source.
>
> What Section 3 of draft-yao-eai-deployment-03 recommends is to 
> generate an alternative address and have it stored on the (sender) 
> server-side.  The user does not have to bother about that alternative 
> address as the server puts it in.
>
> Are you suggesting using VRFY to get the alternative address from 
> another SMTP server?
Yes, if an EAI server has an alternate address associated with an EAI 
address, it can provide it in response to a new SMTP command from 
another EAI server. Apparently some similar ideas of doing this type of 
lookup, for example via LDAP, were explored early on and rejected. Doing 
this securely becomes complicated very quickly.
>
> Regards,
> -sm