To get around the problem with the webmail you should look at using a email application such as outlook, outlook express or mozilla thunderbird.
These will give you the email functionality that you require when sending bulk mail with BCC etc. A word of warning is that these applications by default will pull the mail off the mail server so you wont be able to view it using webmail - you can in each of these applications go into the advanced options and tick the box to say to leave the message on the server (then you can still use webmail).
The server settings required can be found here:
Setting up Outlook Express 6 - Email - Help - Virgin Media