Hi,
The transfer of your domain depends on what type it is.
If it is a .com, .net, .info, .org, you can get it totally moved over to lunarpages. This will be $14.95 per year. It is easier, and you will only recieve 1 bill from lunarpages, instead of 2, from 2 different companies.
If it is a .co.uk or you do not want to move the domain across, you can just contact your existing domain registrar, and tell them to use the lunarpages nameservers for your domain.
They are listed on the FAQ page of
www.lunarpages.com along with instructions on how to transfer from several popular domain registration companies.
If you need more help, just ask, there are lots of people here who have done the same thing before.
The amount of space taken up by your e-mail, is taken out of your webhosting space. e.g. if you are on the standard plan, you would have 500Mb of space, shared between e-mail and webpages.
Mail will not get deleted if it is really old. It's up to you if you want to delete it or not.
You can set a limit on how much space gets used up for each e-mail address on your account in the control panel.
There is a 10Mb limit on e-mail attachments .
Hope that helps