I think i'm actually subscribed to the list under both emails.  But I'm using my gmkarl account.  I have gmail configured to reply with the address the email was sent to (it puts the account address in a header when it does this).

I guess gmail must be picking using some implementation quirk, whether to reply as gmkarl or xloem, to emails sent to one or the other.

I try to pick gmkarl instead of xloem when I remember on this list, so I can try to act less crazy when speaking as xloem, which is one of the email I addresses that i have more software development history as.