cyrus logs

[RJ45]

hello,
it happens that in the maillog I see different log message from sendmail
which delivers mail to cyrusv2.

this happens to the dame user or to different users.
sometimes the log is like:

Mar  2 12:25:48 postino
sm-mta[3269]: i22BPG01003269: to=user at mydomain.com,
delay=00:00:00, xdelay=00:00:00, mailer=cyrusv2, pri=34299,
relay=localhost [[UNIX: /var/imap/socket/lmtp]], dsn=2.0.0, stat=Sent

Mar  2 12:15:40 postino
sm-mta[2072]: i22BFH00002003: to=user at mydomain.com,
delay=00:00:23, xdelay=00:00:01, mailer=cyrusv2, pri=170389,
relay=localhost, dsn=2.0.0, stat=Sent


I use vyrusv2 deliver using /var/imap/socket/lmtp

how come the log from user to user and from mail message to mail message
changes so much randomly ?
isn;t lmtp mechanism always used ?

thanks

Rick