[Exim] Logging of RCPT rejections by remote hosts (550, 554)

Sometimes the following two lines are logged

2004-07-02 12:34:56 1BgKAH-0001wn-HP SMTP error from remote mailer after RCPT TO:<USER@DOMAIN>: host mail.DOMAIN [1.2.3.4]: 550 5.1.1 <USER@DOMAIN>... User unknown
2004-07-02 12:34:56 1BgKAH-0001wn-HP ** USER@DOMAIN R=dnslookup T=remote_smtp: SMTP error from remote mailer after RCPT TO:<USER@DOMAIN>: host mail.DOMAIN [1.2.3.4]: 550 5.1.1 <USER@DOMAIN>... User unknown

But most of the time, only the second one is logged. I cannot find any
differences between the two cases that would justify differences in
logging.

Marcin
--
Marcin Owsiany
porridge@???