I'm the tracker admin for our group. When people reply to NOSY email 
using their favorite mailer, the mail gets sent 'To' the roundup admin, 
me. The 'Reply-To' email attribute should be set to the author of the 
issue.

Attached is a fixed version. A summary of the diff is:
*** 524,537 **** --- 524,537 ----
Set 'In-Reply-To' to the tracker name since it may be useful. Changed 
'Reply-To' to the author, or the from_address as a fallback.

*** 558,574 **** --- 558,563 ----
Removed the 'In-Reply-To' since it is duplicate due the above change.

*** 623,632 **** --- 612,617 ----
Removed duplicate message attributes. To verify I looked at the raw NOSY 
message to make sure that there were no duplicates, and the needed 
attributes were present.