HipChat Server: 1-1 notification emails 'reply-to' field use 'donotreply' address

Summary

When a 1-1 message notification email is sent to your inbox, the 'reply-to' address uses the 'donotreply@domain.com' instead of the address of the user that 1-1 messaged you.

For instance:

Environment

HipChat Server v1.3.x, v1.4.x

Steps to Reproduce

1. Have another user 1-1 message you while you're in an offline status. An email notification will be sent out.
2. Check the email's reply-to field, it will be set to something other than the sender's email address.

Expected Results

The reply-to field should be set to the email address from the user that sent the 1-1 message.

Actual Results

A donotreply email address is used instead of the user's email address.

Workaround

No known workaround currently.