[Dovecot] Duplicate suppression

[Steffen Kaiser]

On Tue, 17 Jan 2006, Greg Trounson wrote:

Hello,

if you maintain the lists "in" your MTA, I'm actually surprised; if the 
lists are handled externally, e.g. mailman, listsrv, the MTA has no way to 
check for duplicate recipients, because the mail is leaving the MTA to the 
list server and the comes back, but is new message now.

Otherwise it is a job for your MDA, because the mail is probably spooled 
into different folders as well.
-> BTW: In environments, when hard linking is working well -- e.g. pure 
IMAP/POP access -- it would be a nice way to handle mass mails; the MDA 
knows that such mails was delivered already and spools it only once, 
hardlinking them all. And if the link would be created into the same 
folder -> just omit it.

I have the problem that I do recieve mails twice from external mailing 
lists, because some MTA in the middle stores them and forwards them twice. 
Therefore I run a script that deletes those duplicates, however: you 
should not rely on the message ID only, because it MUST be unique for one 
MUA for one user during its lifetime (up to the next installation) only, 
hence, there are (were?) MUAs that simple count the message they send.

Bye,

-- 
Steffen Kaiser