I have spent the last 5 days unable to send email through Vodafone. Or, rather, my messages were being delayed then blocked by someone called UCMMAIL.com, whom Vodafone denied all knowledge of. I was using smtp2.vodafone.net.nz. Voda checked my account etc and said it was fine... must have been a problem with my domain name host in the UK. I called the latter put the blame back on Voda. In the meantime the problem continued, and I now have more than 200 'error' messages. Then it struck me that this was actually rather serious...
A company I did not know (ie ucmmail) was blocking my emails, not providing an excuse or explanation, not responding to my enquiries, and not providing any avenue for me to address the problem.
I went back to Voda's helpdesk, who again assured me it wasn't their fault. So I sought some advice and then did a ping on smtp2, and a whois on the resulting IP number. When a whois on UCMMAIL. Bingo - bother were owned by J2 Global.
I spoke to Voda's helpdesk again. It seems that Voda have outsourced their smtp o'seas without even telling their own helpdesk staff.
By pure coincidence (sigh) 20 mins after this became clear I got a message from 'electric.net' saying that my email was no longer being blocked. (I had contacted them 4 days earlier). Seems that ucmmail has outsourced the work.
Never fear, I was told an hour ago that Voda would ring me with an official explanation/apology within half an hour. They're so onto it.