seznam.cz was listed in the banned email list, probably because of the number of spammers that use them. It has been removed from the list for now. centrum.cz is not on the banned list.

Hi,
What User Name did you use & which email addy?
Post it as whoever-at-wherever.cz NOT as you true addy unless you like spam.

You have serious issues on sign up form. I tried at least 10 email addresses and no one worked to be accepted. All have are valid and working. This looks like you ignore cz domain or you ignore seznam.cz and centrum.cz email providers. I had to use gmail account instead to successfull registration. This ain't nice what you do.