Article

Problem

I had a problem with Greylisting and GWIA. Some e-mails were failing to get through, with this error message:

16:32:52 3C4 DMN: MSG 728 Send Failure: 451 4.7.1 message delayed, 
see http://www.greylisting.org ( http://www.greylisting.org/ ) ; 
Please try again later

Solution

The solutions was to adjust the GWIA SMTP/MIME settings for the "Intervals to retry a deferred message". The default GWIA settings were:

20,20,20,240

I changed them to:

3,10,20,20,20,240

That fixed the problem.