[Macpartners] Re: multiple copies received of some e-mails from single list?

[Mark Silis]

Hi Steve,

As a result of the continuing increase in the volume of unwanted e-mail 
the load
on the MIT e-mail system has increased dramatically over the past 
several months. Duplicate message suppression is a server side feature 
which utilizes a database to track e-mail message ids received by user 
(e-mail message ids are a unique identifier distinguishing each 
message). Unfortunately the delivery of each message results in an 
access or write to this database and therefore imposes a significant 
resource impact on the mail system. We have temporarily disabled 
duplicate suppression on the post offices in order to try and ensure 
the timely delivery of e-mail and avoid potential outages as the volume 
of Spam continues to increase. We are currently evaluating several 
possible improvements and are looking to add resources to improve 
overall system performance in the very near future. Once we have 
improved the current situation we will be able to restore the duplicate 
suppression. Thank you and everyone for their continued patience as we 
work through these difficulties.

-- Mark

On Apr 28, 2004, at 6:15 PM, Stephen Dowdy wrote:

> So the $10,000 question might be:   Why is duplicate suppression 
> turned off on the PO servers?    Can it be turned on?
>
>
> At 04:02 PM 4/28/2004 -0400, Laura Baldwin wrote:
>
>> If you're on a mailman list twice (for example, because you're on the
>> list with your own address, and then another list you're on is on the
>> list), then you'll get two copies.
>>
>> This is because duplicate suppression is currently off on the PO
>> servers, so the duplicates aren't being pruned out the way we're used
>> to.
>>
>> Additionally, moira lists prune duplicates before sending messages,
>> while mailman can't, so when a moira list gets converted to mailman,
>> you see duplicates that you didn't before.
>>
>> If there's a particular list that a particular person is getting a
>> duplicate message from, accounts at mit.edu can generally track down why
>> (that is, what the duplicate entries are).
>>
>> -Laura Baldwin
>
>