2. Is there a ban on donations from foreign interests to candidates?

Article 12.3 & 5.2, Political Parties Act, the amended version of law in force from 23.03.2015, No. RT I 1994, 40, 654.

12.3 (8) donations by aliens, except for donations by persons holding the permanent right of residence or the status
of a long-term resident in Estonia.

§ 5.2. (3) The sources of funding of the election campaign of a single candidate include:
1) donations made on the terms and conditions laid down in this Act; (donation can be voluntarily given by a natural person who is a citizen of the Republic of Estonia or has the permanent right of residence or the status of a long-term resident in Estonia out of their assets to a political party or a member thereof for the purpose of supporting the activities of the political party)
2) personal property of the single candidate.