[MlMt] duplicate messages on move to other mailbox

[Benny Kjær Nielsen]

On 23 Oct 2015, at 15:05, Jason Davies wrote:

> Two Macs (laptop, Mac Pro) using Mailmate at different times of teh 
> day. I sat down and created some rules to help filter messages on both 
> machines. Sometime just after that I started noticing duplicates 
> appearing after I move messages to different folders.

If two installs of MailMate have the same rules to move messages then 
there is a race condition. Moving a message is not quite an atomic 
action. If the two installs see the same message at the same time then 
they are both going to try to move it (if a rule matches). One of them 
is probably going to fail with most IMAP servers, but MailMate detects 
this error and instead the message is explicitly uploaded to the 
destination mailbox (generating the duplicate).

A workaround could be to introduce a delay in one of the email clients 
by creating an alternative Inbox (smart mailbox) with messages more than 
x seconds old. Then add the rules to this mailbox on one of the 
machines.

(MailMate could cancel a move if it finds an identical email in the 
destination mailbox, but this would also be a hack -- also MailMate is 
currently not very good at locating identical emails.)

-- 
Benny