[Dovecot] Marking as Read causes Body.Peek on ALL messages - Reasonable?

[Daniel Watts]

>> I've noticed when I select a folder of messages (Thunderbird) and 
>> mark them all as read (or unread) it produces the following IMAP 
>> transcript:
>>
>> Source    Destination    Info
>> c.c.c.c    s.s.s.s    Request: DONE
>> s.s.s.s    c.c.c.c    Response: 20 OK Idle completed.
>> c.c.c.c    s.s.s.s    Request: 21 uid store 1:20 -Flags (\Seen)
>> s.s.s.s    c.c.c.c    Response: * 1 FETCH (UID 1 FLAGS (\Recent 
>> NonJunk))
>> c.c.c.c    s.s.s.s    Request: 22 UID fetch 2 (UID RFC822.SIZE 
>> BODY.PEEK[])
>> s.s.s.s    c.c.c.c    Response: * 2 FETCH (UID 2 RFC822.SIZE 1339 
>> BODY[] {1339}
> ..
>
> Looks a bit stupid. But I'd guess it's related to Thunderbird being 
> configured to download mail when reading it and it treats setting 
> \Seen the same as reading it. Just a guess though.
It becomes a bit of a problem when done in a folder of 40,000 messages - 
locks up the program for ages and hammers the server a bit too.
>
>> Is this reasonable? I thought it would be possible to just send a 
>> list of message UIDs and say mark these as /seen /unseen etc.
>
> Sure, it would be possible. Also if Thunderbird really wants to fetch 
> these messages' bodies, it could have done it using a single command 
> instead of 20 separate ones..
>
Perhaps it does it one by one incase there are a lot of messages.... but 
it could chunk them at least.

Timo - thanks as always for your help with this, particularly as it is 
slightly OT.
Ever thought about writing your own mail client? =) Perhaps 
LightningDove! The more I use Thunderbird the more I find it totally 
insane. Still better than going back to Outlook (thought not tried 2007 
yet).

Dan