On Friday 10 Dec 2004 5:26 pm, Rich Kulawiec wrote:
When an incoming SMTP connection is made to one of Verizon's MX's, they allow it to proceed until the putative sender is specified, i.e. they wait for this part of the SMTP transaction:
I don't think this is the issue, as we aren't getting that far in the transaction. Inspection suggests that the anycast announcements in the UK were pointing to a server that wasn't accepting email. I believe here the problem is using anycast, and not providing a backup system not using anycast. The previous case I'm aware of was when bits of the NE USA lost ".org" because they only had anycast DNS servers (and still do AFAIK), and the announcement messed up. Whilst I plead ignorant of the technical details of anycast, strikes me that it is clearly more complex, and thus more prone to failure, and these failures are potentially less obvious.