I am starting my PhD and have two equivalent supervisors at different universities in different cities. I am going to city A first and then later to B and so on.
What is the etiquette regarding emails? Is it impolite to address emails to just one supervisor even if it's not an important subject like informing that I arrived in city A? Should I always send emails to both of them?
I think that asking won’t hurt. But that said, just because two PIs are jointly advising a student on a degree does not entitle one to be privy to all exchanges with the other. Or put another way: just because you have two advisors doesn’t mean you lose all rights of privacy when communicating with either one of them. Of course sometimes information concerns both, so an email addressed to both is appropriate.
Actually, you should ask them directly. Different people will have different preferences. Alternatively you could start out copying both and then stop if either of them suggests it.
But, it is probably best to keep them equally informed about your progress and current activities.
Questions that are more in the purview of one of them than the other might be directed at the more appropriate person, I suppose.
The answer here of Mario Niepel reminds me that I was only thinking of technical communications, not personal ones.
