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 <aki.tuomi at dovecot.fi>
wrote:
>
>
>> On June 10, 2017 at 5:58 AM Peter West <lists at pbw.id.au>
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
>> pbw at pbw.id.au
>> 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
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What's your LDA? Aki> On June 10, 2017 at 11:01 AM Peter West <lists at pbw.id.au> wrote: > > > 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 <aki.tuomi at dovecot.fi> wrote: > > > > > >> On June 10, 2017 at 5:58 AM Peter West <lists at pbw.id.au> 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 > >> pbw at pbw.id.au > >> 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 >
Not sure what you mean. I?m using lmtp to send messages to Dovecot from Postfix.> On 10 Jun 2017, at 6:08 pm, Aki Tuomi <aki.tuomi at dovecot.fi> wrote: > > What's your LDA? > > Aki > >> On June 10, 2017 at 11:01 AM Peter West <lists at pbw.id.au> wrote: >> >> >> 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 <aki.tuomi at dovecot.fi> wrote: >>> >>> >>>> On June 10, 2017 at 5:58 AM Peter West <lists at pbw.id.au> 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 >>>> pbw at pbw.id.au >>>> 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 >>-------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 235 bytes Desc: Message signed with OpenPGP URL: <http://dovecot.org/pipermail/dovecot/attachments/20170610/1a653fb0/attachment.sig>