Atsuko Samukura
Mahavir shrank a bit at the clear disappointment, but he hadn’t done anything wrong, right…? He wasn’t sure what to make of her next statement, either, so he just nodded along.

“Ah, the contents of the letters… Of course, I don’t read them myself, so I can only say what’s been shared with me, or what I can, um, assume from the Passengers’ reactions. There’s been quite a variety of those, so I couldn’t rightly guess what the letters may say to anyone in particular. Most are as personal as you’d expect, well, personal mail to be, but I couldn’t claim any more of a trend than that.”

“I have no way to tell how long someone has been on the Train—I apologize. If it helps, I don’t believe I’ve seen any of you before…?” That almost certainly didn’t help, did it. Oof. “But I suppose there aren’t a lot of, ah, repeat customers to begin with.”
Oh good, something he actually had an answer to!

“They can! There will still be a time lag, as you’d expect for any kind of physical mail—or, er, possibly moreso than usual. But I swear I’ll do everything in my power to have it sorted efficiently to reach its destination!”