A seldom used DNS Blacklist is causing email delivery problems for some of our customers.  Apparently this list has been abandoned by the operator.  It had been returning a Not listed result for all IP addresses checked.  As of a few days ago, the domain registration lapsed and Network Solutions pointed the DNS servers to: [...]

After a strange week, SMTP transaction times have returned to normal levels.  Friday has averaged 4.5% faster response than expected.  As expected, we see a sharp drop-off at 4:00pm CT (5:00pm in the East), as people flee their cubicles for some R&R.

The trend we saw beginning Monday morning continues.  Tuesday is winding down with an unusual 31% increase in SMTP transaction times.  We have seen no unusual reports from our email user base, but continue to look into the root cause and will post more information when we get it. The purple line shows the profile [...]

We have monitored a very large increase in SMTP transaction times throughout the day, peaking at 3:00pm CT.  SMTP transaction times for the day are 22% elevated over a typical Monday.  The trend started at exactly  9:00am CT as users returned to their desks from the work week.  No immediate cause is known.