Well, our government definitely uses "electronic registry" as evidenced by:
http://www.hrad.cz/cs/kontakty/elektronicka-podatelna.shtmlIt doesn't seem like the best translation to me, however. Podatelna doesn't have anything to do with registering. If you ask me, I'd say it's a place where many people can submit documents.
This makes me think that a more accurate translation would be "electronic filing system" or "electronic filing portal/gateway" with possible modifications such as substituting "e-filing" for "electronic filing" or moving the words around like "a portal for electronic filing". Or possibly using "document submission" instead of filing?
(Most of the expressions seem to be actually used on the Internet for similar purposes in English speaking countries )
I simply don't think that registry quite matches with podatelna.
Nevertheless, it may still be a good choice if the recipient actually calls it "electronic registry".