VP - I had this trouble with the VMC card. So I set up 2 accounts in Outlook Express; one is 'Virgin Net' which is a POP3 and uses mail.virgin.net as both the incoming and outgoing mail server. I had difficulties using some wi-fi hotspots to send e-mails until Virgin advised me that I should tick 'My server requires authentication' in the 'Outgoing mail server' box.
For the VMC card (also POP3), the other account ('VMC') uses mail.virgin.net for the incoming mail server, but the outgoing server has to be set to send.vodafone.net
Rather than click 'Send/Recv', click on the down arrow and then on the appropriate account name.
It certainly wasn't the 'plug and play' which Vodafone alleged it would be!
The reliability of LH lounge Vodafone D2 wi-fi hotspots - or rather their associated computers - is also rather poor in my experience.