Thanks for that Aki. Follow-up question. I tried to initiate compression by adding
mail_plugins = $mail_plugins zlib
plugin {
zlib_save_level = 6
zlib_save = xz
}
to dovecot.conf. I restarted dovecot and sent one message to the server, and
one message from the server. Neither was compressed. I changed the save type
to
zlib_save = bz2
and repeated. This time the message received (in
/var/vmail/<host>/<username>/cur) was not compressed, but the message in
/var/vmail/<host>/<username>/.Sent/cur was bzip2 compressed.
Why is the received mail not being compressed? Is this the point of the
discussion about compressing old mails?
> On 10 Jun 2017, at 4:43 pm, Aki Tuomi <[email protected]> wrote:
>
>
>> On June 10, 2017 at 5:58 AM Peter West <[email protected]> wrote:
>>
>>
>> Concerning Maildir, the wiki page on compression has this:
>>
>> All mails must have ,S=<size> in their filename where <size> contains the
>> original uncompressed mail size, otherwise there will be problems with quota
>> calculation as well as other potential random failures. Note that if the
>> filename doesn’t contain the ,S=<size> before compression, adding it
>> afterwards changes the base filename and thus the message UID. The safest
>> thing to do is simply to not compress such files.
>>
>> Further down on the same page is this:
>>
>> If the file does exist, rename() (mv) the compressed file over the original
>> file.
>> • Dovecot can now read the file, but to avoid compressing it again on
>> the next run, you'll probably want to rename it again to include e.g. a "Z"
>> flag in the file name to mark that it was compressed (e.g.
>> 1223212411.M907959P17184.host,S=3271:2,SZ).
>>
>> These comments seem to contradict each. Or is there a difference between
>> adding the size specifier to the filename and adding a Z flag to the end of
>> the file name?
>>
>> --
>> Peter West
>> [email protected]
>> And the great throng heard him gladly.
>>
>
> Keyword is 'base filename'. From the wiki, "The standard filename definition
> is: "<base filename>:2,<flags>".". Z is a flag.
>
> Aki
signature.asc
Description: Message signed with OpenPGP
