I suspect he is. In every email conversation I've had with him since 1998, I get this auto-reply (or something like it; it has likely morphed somewhat over the years):
I am not on vacation, but I am at the end of a long time delay. I am located somewhere on Earth, but as far as responding to email is concerned, I appear to be well outside the solar system.
After your message arrives at gnu.org, I will collect it in my next batch of incoming mail, some time within the following 24 hours. I will spend much of the following day reading that batch of mail and will come across your message at some point. If I can write a response for it immediately, the response will go out in the next outgoing batch--typically around 24 hours after I collected your message, but occasionally sooner or later than that. As a result, you should expect a minimum delay of between 24 and 48 hours in seeing any response to your mail to me.
If you are having a conversation with me, please keep in mind that each message you receive from me is probably a response to the mail you sent 24 to 48 hours earlier, and any subsequent mail you sent has not yet been seen by me.
