Emails Randomly Reaching Destination

Gerard Cleary gcle at
Sun Mar 21 22:03:20 GMT 2010

On Sat, 20 Mar 2010 00:05:39 Vernon Webb wrote:
> When sending emails out they sometimes reach their destination and
>  sometimes not.
We have a Linux mail server which runs milter-greylist among other things. 
Some of our smaller (~20 users) customers reported your scenario with perhaps 
50% of their eMails getting through.  An analysis of our mail logs showed that 
their mail server (invariably MS Exchange) was not handling bounces properly. 
I checked the MS Knowledge Base and found greylisting mentioned in conjunction 
with an Exchange setting called Glitch-Retry-Interval.
I sent the MS Knowledge Base document to the customer who usually has to call 
in IT resources to change the Exchange configuration files. When this 1 minute 
change is made to the Exchange Server, their eMails get to us 100% of the 
My conclusion is that MS Exchange doesn't handle bounces "out of the box".


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