Hello everyone.
As this seemed like a well discussed issue I thought it a good idea to post some information that might clarify a few points.
VM state clearly on their Website under the section Email help the following statement, why you might not be able to send email:
"You are not connecting to Virgin Media when trying to send email. This will give an error code of 550 or 'Relaying mail is not allowed'."
http://www.virgin.net/helpme/email/questions/12.html
Vodafone have always been sensitive to the fact that some ISP's restrict what kind of activity you can do if your not connected via their tethered connection. With this in mind Vodafone provide a free standing smtp server with the address send.vodafone.net No usernames or passwords are required to use this server and it will still appear at the other end that you're sending from your VM account. You also use the standard 25 as your smtp port.
Whilst I can not comment on VM's part in this issue, I can assure you that our Internet APN provides useable access to pop3 and IMAP accounts. I am quite happily using my Gmail account on my Vodafone handset
If you can use other POP3 and IMAP services on your device through Vodafone, then it's highly unlikely to be an issue with our network.
One last little bit of information. If you're using the email client on your handset to send/receive email then you need to be using internet access and not wap. The name for Vodafones internet APN is simply
internet in lower case with the username
web and password
web. Again these are in lower case.
I hope this information is of use!
PhobosDeimos
Vodafone UK