On 12.2.2012, at 15.43, Charles Marcus wrote:

One thing that concerns me right now about my main clients site that I will soon be migrating from courier-imap to dovecot is the message/thread a while back about the problems with SIS and backups.

I'm planning on creating a new "backup" mail storage backend, where you could basically run:

doveadm backup -u user@domain backup:

And it would output the user's messages to stdout (or to some file). So it would be similar to e.g. PostgreSQL's pg_dump. Then for restoring you can use the same input for "doveadm import". So in the backups there would be no deduplication, unless implemented by the backup software.

I am trying to decide between using dovecot's SIS, or using mimedefang's ability to replace attachments with hyperlinks to them (storing them on a webserver - still not clear on exactly how it works or the security implications of doing so). It looks like using mimedefang would eliminate the problem with backups, and would provide the added benefit of eliminating large file attachments for external recipients as well, however I'm concerned about security - ie, how do you limit access to these attachments to only the recipients of the message with the hyperlink in it?

As long as the URL is random enough it shouldn't be possible to guess the links. But if they're HTML mails and such then hyperlinks would send the referrer-url to the next site. I guess you could also add HTTP authentication.

On Sun, Feb 12, 2012 at 05:58:20PM +0200, Timo Sirainen wrote:

doveadm backup -u user@domain backup:

And it would output the user's messages to stdout (or to some file). So it would be similar to e.g. PostgreSQL's pg_dump.

So only full backups, no incremental backups? Then what's the benefit over just copying the files (of a snapshot)?

-jf

Thanks for 2.1.0 Timo

Looking forward to beta-test 2.2 :)

Le 12/02/2012 05:45, Timo Sirainen a écrit :

On 12.2.2012, at 7.42, Timo Sirainen wrote:

...

I'll release v2.1.rc6 in maybe 16 hours or so. If no problems are reported in it after a few days I'll just change version to 2.1.0. So now's a great time to try the latest v2.1 hg version to see if there are any problems.

Oh, and if you want to try out some new things in v2.1.rc6, here's the biggest changes so far:

• Added automatic mountpoint tracking and doveadm mount commands to manage the list. If a mountpoint is unmounted, error handling is done by assuming that the files are only temporarily lost. This is especially helpful if dbox alt storage becomes unmounted.
• Expire plugin: Only go through users listed by userdb iteration.

Delete dict rows for nonexistent users, unless

expire_keep_nonexistent_users=yes.

• LDA's out-of-quota and Sieve's reject mails now include DSN report instead of MDN report.

• LDAP: Allow building passdb/userdb extra fields from multiple LDAP

attributes by using %{ldap:attributeName} variables in the template.

• doveadm log errors shows the last 1000 warnings and errors since

• Improved multi-instance support: Track automatically which instances are started up and manage the list with doveadm instance commands. All Dovecot commands now support -i

Dovecot was started. parameter to

select the instance (instead of having to use -c ). See instance_name setting.

• doveadm mailbox delete: Added -r parameter to delete recursively
• doveadm acl: Added "add" and "remove" commands.

• Updated to Unicode v6.1

• mdbox: When saving to alt storage, Dovecot didn't append as much data to m.* files as it could have.
• dbox: Fixed error handling when saving failed or was aborted
• IMAP: Using COMPRESS extension may have caused assert-crashes
• IMAP: THREAD REFS sometimes returned invalid (0) nodes.
• dsync: Fixed handling non-ASCII characters in mailbox names.