On Thursday 26 April 2007 00:43, you wrote:
A chap I know (for some reason) set his source port for queries to be port 53 and his DNS queries started to fail.
It was the default source port for DNS queries in some versions of BIND. And may well still be (I don't do those versions of BIND). The main reason for changes was that you need root privilege to bind to those ports in traditional Unix model, and people wanted to run DNS as a non-root user. The more general bitbucketing of hotmail email is well known (try Google or Yahoo! search engines to find out more). In general people should be advising against using Hotmail until Hotmail fix the bitbucketing issue, as encouraging it will undermine the reliability of email. Presumably eventually (like AOL did) Hotmail will bitbucket some email important enough to make them realise the error of their ways, meanwhile Hotmail users get a service which is worth about what most of them pay for it.