The following is information I have from a friend who I met up with today who works in the telecommunication industry for a major infrastructure hardware vendor, I know it is always dubious to quote second hand information, but I thought that anyone who is concerned about this and may have better access to means of corroborating it might want to check it out.
This friend has been told by a contact within his company that the C.O.S have business interests in GMX and Web.de.
It may be possible that they are only minority share holders in these businesses, but from the way he understood it they are significantly more involved than that.
I was going to sign up for a better, shinier IMAP account anyway, (POP sucks), so I think i'll use this as the excuse to take the time to finally do it.
I won't say anymore, apart from that I have just done a Google search using three terms: Scientology, GMX and web.de and got a link to the German C.O.S site. The only centres that didn't have email addresses using an official scientology domain used gmx.de and web.de addresses.