Messed up dovecot mail store, need some repair advice

[Gerben Wierda]

> On 22 Oct 2016, at 19:04, Aki Tuomi <aki.tuomi at dovecot.fi> wrote:
> 
> 
>> On October 22, 2016 at 7:51 PM Gerben Wierda <gerben.wierda at rna.nl> wrote:
>> 
>> 
>> Hello folks,
>> 
>> I have an older dovecot 2.0 (which I will migrate to a 2.2 asap, but at this point in time I need a fix). This is a dovecot 2.0 that came with Mac OS X 10.8.5 Server 2.2.5.
>> 
>> Today, my spam/virus filtering (clamav) on the Server broke down. As a result, all my meesages got the ***UNCHECKED*** tag added to each subject. That was clearly unacceptable. SO, for the tim ebeing I have set that tag to undef so the tag is no longer added. But I also wanted to repair the messages that already ended up in dovecot 2.0
>> 
>> So, I did something simple: stopped all mail services on the server, went into the dovecot mail store and edited the messages. I first tried with one small ccount and it seemed OK. But now my mail client is experiencing problems with the messages (cannot display) and I think I've been to simplistic. I have for instance notedthat th esizeof the message is part of the filename. So, I can change these of course, but probably I need to change more.
>> 
>> Can someone enlighten me how I can repair the broken data store?
>> 
>> Thanks,
>> 
>> (Foolish) Gerben
> 
> I think your best bet is to delete dovecot.index* and run dovecot index -u username. Or revert all your changes. Depending what mail store you are using, this might lose any flags on your mails, such as \Read.

Thanks. Losing 300 flags and unread on thousands of emails was not a preferred scenario.

I was able to repair by 
- turning dovecote (and other mail services) off
- find all message files that were changed in a certain period
- check all their names against their file sizes (this found me the edited ones)
- returning the ***UNCHECKED*** string to the Subject lines making the file sizes equal to the size as reported in the name of the file 

Which leaves me with something I would really like: change the subject line of 5-10 messages in dovecot, without destroying everything.

I was thinking about the following scenario:
- create a separate mailbox REPAIR within user X’s mail store (the INBOX, btw, is named ‘cur’)
- move all to be changed messages there using the mail client
- kill the mail client
- stop dovecot
- edit the messages and change the names of the files so the S= W= parts are in line with the new content. (I understand S, but what is W?)
- run “devoid index -u user REPAIR”
- start dovecot
- start email client (potentially, reload the entire mail store for that user)

Would that work?

G