Marian, thanks, that’s interesting. The postal card you describe would not be self-authenticating under federal evidence law, though I can’t speak to California law. It’s possible there may therefore have been a technical evidentiary objection to the proof of service, though it seems the facts were not in dispute—just their consequences.

In the circumstances of the case I agree with you that there doesn’t seem to be a strong due process argument against the sufficiency of the service.

However, when a Russian citizen moves permanently abroad they are supposed to (but seldom do) notify the authorities that they are no longer registered at a particular address in Russia and are no longer a resident. It would be interesting to know whether he did so. Even if he had though, I think a court in Russia would have enforced the service, because contracts here typically say that X address will be the appropriate address for notifications and service, unless and until the party changing addresses notifies the other party differently. And notification of change usually has to be formally made and signed according to whatever procedure is written in the contract. Thus, if Yakovlev didn’t notify Alfa, the problem is his.