That makes as much sense as having a [censored] trading post in Washington D.C. for Iran, Cuba, and North Korea that is placed right next to a fuel depot with a sign hanging on the front gate that says 'No, we're ok.'
Thanks for that non-sequitur Roaming Nomad. I have not visited the Iranian, Cuban or North Korean Embasies on Washington DC. I suspect they exist whether or not they are currently in use simply because the US recognises the countires exist whatever it thinks about their regimes - and generally all trading partners have embassies of one sort or another. Why should it be different in Tamriel?
Generally major diplomatic presences have 2 locations. One is the Embassy proper where the Ambassador resides and the other is the Consulate that deals with citizens of its country and their personal needs re certification etc ...
I would expect there to be some sort of representation in the major cities of Nirn if only because teleportation makes instantaneous travel possible despite whatever limitations are artificially imposed by different regimes - and given the size of the Empire and its fleet and trading nature - the importance of Embassies / other appropriate stations and their likelihood only increases. At the least overseas trading partners would establish trading offices there.
As for emnities? all the more likely to have representation - right up to the declaration of hostilities.