Is a typed vow of a Gentile binding?

Question

If a gentile in an email 'types' that he promises not to do something [1]doesn't use G-d's name 2]has no intention to keep the oath 3]but doesn't say bli neder either] is that vow binding? Some hold that writing counts as speaking. Others do not. Possibly even for those who rule that writing counts as speech, maybe typing is different. But does one need to find a rabbi to nullify that covenant?