[exim] More log questions

Hello,

I've got more questions about the Exim main log:

1. The documentation says about delivery logging (ch 53.7):

> When two or more messages are delivered down a single SMTP connection, an asterisk follows the IP address in the log lines for the second and subsequent messages.

How does that look like in the log file? I'm not sure where exactly that
asterisk would appear. I haven't seen one in my logs but it sounds like
it could break my parser.

2. I see log lines like these:

> 2020-12-27 08:02:06 1ktQ44-0074VW-Qi => username@??? <othername@???> F=<...> R=dnslookup T=remote_smtp ...
> 2020-12-27 17:39:25 1ktZ4m-008ljc-Is => user.name@??? <User.Name@???> F=<...> R=dnslookup T=remote_smtp ...

It's not documented what these two addresses mean. From the second
example I guess that the address in upper case is the one entered by the
sender and the first one is what's really used instead. I don't
understand the first line though.

Which of the two addresses, if present, is the one I should care about?

-Yves