Based on purely visual non-scientific observation (top), it seems my smtpd processes on my MX hang around much longer in (Debian) 2.5.5 than they did in (Debian) 2.3.8. In 2.3.8 Master seemed to build them and tear them down very quickly after the transaction was complete. An smtpd process' lifespan was usually 10 seconds or less on my 2.3.8. In 2.5.5 smtpd's seem to hang around for up to 30 secs to a minute.
Local shows very speedy delivery. Is this "long" smtpd process lifespan normal for 2.5.5 or did I do something screwy/wrong in my config? relay=local, delay=2.2, delays=2.2/0/0/0.01, dsn=2.0.0, status=sent relay=local, delay=0.32, delays=0.29/0.02/0/0, dsn=2.0.0, status=sent relay=local, delay=0.77, delays=0.75/0.03/0/0, dsn=2.0.0, status=sent relay=local, delay=0.26, delays=0.25/0/0/0.01, dsn=2.0.0, status=sent relay=local, delay=0.64, delays=0.62/0.03/0/0, dsn=2.0.0, status=sent relay=local, delay=0.26, delays=0.25/0/0/0, dsn=2.0.0, status=sent -- Stan