Active / Passive redundancy?
> Your outbound smtp service being blocked for delivery to hotmail (and I presume lots of others) because you have IP addresses on spamhaus blacklist again.
Is it too simple for a hosting provider to have more than one address (or set of addresses) for their outbound SMTP, with the spare set kept as, well, spares? So that if one or all of the main ones get onto a block list they can be swapped over quickly - in minutes?
They would of course have to block whichever it is of their customers that got them on the naughty list first (otherwise the spare addresses would get blocked as well) but since that customer is likely to be the one sending millions of messages per second they shouldn't be too hard to find.