Unicount never shares your information with third parties without your prior consent.
Estonian Business Register though sells data of newly registered companies to local service providers who send their offers to your public company email address. This is legal but annoying. Your company email is also part of the free information available to public. Read more here.
Please note that starting from 20 May 2020 Unicount does not reveal your email to the Business Register if you ordered contact person service when registering a company via Unicount. You can be sure that no spam reaches your personal and company email inserted during the registration. You can set up your company’s spam proof eesti.ee email in the Business Register whenever you wish to do so. Until then your company’s public email is the spam proof eesti.ee email of Unicount (email@example.com) and Unicount forwards all the necessary government emails.
You can change your official company email address to eesti.ee address which is given by the government. Company email would look like firstname.lastname@example.org and non-government IP addresses cannot send emails to this address. To do this you need to log-in to Business Register and activate eesti.ee email address with forwarding to your actual email address.
It will not solve the problem of your initial email being already in the hands of spammers though. As a precaution you may use a temporary or less relevant email address when registering a company.