Hmm I would email back once..and leave it at that. I have a soldier I'd sent boxes to, pretty regular guy...we were emailing back & forth, too. He went to another FOB with limited (actually, I think it's non-existent) internet access & I didn't hear from him for about a month, then got an email apologizing (to me, for heaven's sake! I feel bad when they do that) for his tardy reply. I assured him it was totally fine. I'm still sending a box a month & a letter to go with each, though I've not heard from him since the last email (mid-December). Don't want to clutter up his inbox, he'll answer when he can. And I send letters when I don't send a box (every other month). The guys always enjoy correspondence, even when they can't always answer back.
I can't even begin to imagine how hard it is to get a free moment there, or the strength to sit there & keep up with their communication with friends, family, etc..especially after a grueling day-I'm sure I would just want to curl up & sleep! I understand your worry, though & it doesn't go away, even after the "new"ness disappears, even when you realize the extreme difficulties of their lives there. So, ditto on what Deni said, too.
Hope you have a lovely weekend.
Take care,
Steff
"This new learning amazes me, Sir Bedevere. Explain again how sheep's bladders may be employed to prevent earthquakes." M. P.