[exim] Mail queue

Can anyone tell me what the YY, YN etc next to the email address mean? Is it
described in the documentation?

1DWXBj-0007wP-G5-H
root 0 0
<xxx.xxx@???>
1115979275 0
-helo_name client06
-host_address XX.XXXXXXXX
-host_name XXXXXXXX
-interface_address XXX.XXX.XXX.XXX
-received_protocol esmtp
-body_linecount 56
YY email1@???
YN email1@???
NY email1@???
NN email1@???