I hate making posts like this!
My ISP made some kind of a change late last week and all emails sent from (at minimum) yahoo.com are being silently dropped. Other mail *seems* to be unaffected, but of course I'm unaware of emails I have not received!
If you've sent me an email in the last 5 days and I've failed to respond, it may be that I've not received it. Grr...
