Thank you for confirming. That was the conclusion I came to, particularly after seeing the structure of Maildir mailboxes and how the individual messages were encrypted. Clearly it would be difficult to do the same with an unlimited number of messages stored in a single file.

A followup question if I may. I probably should just start another thread, but, how difficult is it to convert to Maildir? Any gotchas? Any differences in how to manage the server? How effective is the mb2md? Not looking for a cookbook, just an opinion on whether it is worth converting. We've used mbox format going back before CentOS 5, so change is hard. Environment is CentOS 7, Dovecot, Sendmail, Pigeonhole, MailScanner, Mailwatch SQL, Thunderbird clients.

Thanks,Doug On Friday, February 11, 2022, 09:31:09 AM EST, Aki Tuomi aki.tuomi@open-xchange.com wrote:

On 11/02/2022 16:26 cincodemayo_67@yahoo.com cincodemayo_67@yahoo.com wrote:

Hi,   

My Dovecot server of many years has been set up to use mbox email folders. I want to implement mail-crypt and after banging my head against a wall for a few days trying to get mail-crypt to work I decided to try it against a test instance of my server that I reset to use Maildir format and mail-crypt worked instantly.
Does mail-crypt work with mbox format mail folders, or am I wasting my time unless I switch over to Maildir?  The documentation at https://doc.dovecot.org/configuration_manual/mail_crypt_plugin/ doesn't explicitly say Maildir is required.
Thanks in advance,
Doug

Mail crypt will not work with it. Mbox format has limited support of features. --- Aki Tuomi

Unfortunately, this document doesn't really address the OP's need, which is to migrate mailbox formats on the same server. Now migrating to a new server would work, where the new server was setup to use maildir as the default.

Maybe a new section could be added talking about this situation in more explicit terms, with some real examples of conversions?

John

Aki> https://doc.dovecot.org/admin_manual/migrating_mailboxes/

Aki> Aki

...

On 11/02/2022 21:29 cincodemayo_67@yahoo.com cincodemayo_67@yahoo.com wrote:

Thank you for confirming. That was the conclusion I came to, particularly after seeing the structure of Maildir mailboxes and how the individual messages were encrypted. Clearly it would be difficult to do the same with an unlimited number of messages stored in a single file.

A followup question if I may. I probably should just start another thread, but, how difficult is it to convert to Maildir? Any gotchas? Any differences in how to manage the server? How effective is the mb2md? Not looking for a cookbook, just an opinion on whether it is worth converting.

We've used mbox format going back before CentOS 5, so change is hard.

Environment is CentOS 7, Dovecot, Sendmail, Pigeonhole, MailScanner, Mailwatch SQL, Thunderbird clients.

Thanks, Doug On Friday, February 11, 2022, 09:31:09 AM EST, Aki Tuomi aki.tuomi@open-xchange.com wrote:

...

On 11/02/2022 16:26 cincodemayo_67@yahoo.com cincodemayo_67@yahoo.com wrote:

Hi,

My Dovecot server of many years has been set up to use mbox email folders. I want to implement mail-crypt and after banging my head against a wall for a few days trying to get mail-crypt to work I decided to try it against a test instance of my server that I reset to use Maildir format and mail-crypt worked instantly.

Does mail-crypt work with mbox format mail folders, or am I wasting my time unless I switch over to Maildir? The documentation at https://doc.dovecot.org/configuration_manual/mail_crypt_plugin/ doesn't explicitly say Maildir is required.

Thanks in advance,

Doug

Mail crypt will not work with it. Mbox format has limited support of features.

Aki Tuomi

Thanks for that Marc. I'm guessing that mdbox format isn't compatible with mail-crypt for the same reasons as mbox. Can anyone confirm? The built in dovecot dsync utility so far looks much more promising. I have about 20 users consuming less than 50GB of email storage. I tend to doubt on a good sized Linux server I will run into storage issues or run out of inodes.

For those still following along, mb2md didn't seem to work well for me. It lost or corrupted enough email that I gave up on it. Less than 1%, but still too high. --Doug

Marc wrote: What you should also consider if you are using some distributed filesystem or block devices, is that maildir format created lots of small files, which in some storage backends will give you quite a bit of storage amplification. That is why I choose for the mdbox format.

On Friday, February 11, 2022, 05:02:25 PM EST, cincodemayo_67@yahoo.com <cincodemayo_67@yahoo.com> wrote:  

Agreed I am looking to migrate in place, if I migrate at all. I'm still researching the benefits (aside from mail-encrypt) to using Maildir instead. It may be the new default, but to me it is an unknown. I am going to play with the mb2md utility (https://centos.pkgs.org/7/epel-x86_64/mb2md-3.20-17.el7.noarch.rpm.html) in a test instance to see if migrating in place is a feasible.

Thanks for your responses, very much appreciated.

On Friday, February 11, 2022, 03:57:39 PM EST, John Stoffel <john@stoffel.org> wrote:  

Unfortunately, this document doesn't really address the OP's need, which is to migrate mailbox formats on the same server.  Now migrating to a new server would work, where the new server was setup to use maildir as the default.

Maybe a new section could be added talking about this situation in more explicit terms, with some real examples of conversions?

John

Aki> https://doc.dovecot.org/admin_manual/migrating_mailboxes/

Aki> Aki

...

On 11/02/2022 21:29 cincodemayo_67@yahoo.com cincodemayo_67@yahoo.com wrote:

Thank you for confirming. That was the conclusion I came to, particularly after seeing the structure of Maildir mailboxes and how the individual messages were encrypted. Clearly it would be difficult to do the same with an unlimited number of messages stored in a single file.

A followup question if I may. I probably should just start another thread, but, how difficult is it to convert to Maildir? Any gotchas? Any differences in how to manage the server? How effective is the mb2md? Not looking for a cookbook, just an opinion on whether it is worth converting.

We've used mbox format going back before CentOS 5, so change is hard.

Environment is CentOS 7, Dovecot, Sendmail, Pigeonhole, MailScanner, Mailwatch SQL, Thunderbird clients.

Thanks, Doug On Friday, February 11, 2022, 09:31:09 AM EST, Aki Tuomi aki.tuomi@open-xchange.com wrote:

...

On 11/02/2022 16:26 cincodemayo_67@yahoo.com cincodemayo_67@yahoo.com wrote:

Hi,

My Dovecot server of many years has been set up to use mbox email folders. I want to implement mail-crypt and after banging my head against a wall for a few days trying to get mail-crypt to work I decided to try it against a test instance of my server that I reset to use Maildir format and mail-crypt worked instantly.

Does mail-crypt work with mbox format mail folders, or am I wasting my time unless I switch over to Maildir? The documentation at https://doc.dovecot.org/configuration_manual/mail_crypt_plugin/ doesn't explicitly say Maildir is required.

Thanks in advance,

Doug

Mail crypt will not work with it. Mbox format has limited support of features.

Aki Tuomi

Many thanks Aki. Good to know. I'll look into mdbox as well.

Doug

On 2/17/2022 11:06 AM, Aki Tuomi wrote:

mdbox is compatible with mail crypt plugin, since it works differently compared to mbox.

Aki

On 17 February 2022 15.58.13 UTC,"cincodemayo_67@yahoo.com" cincodemayo_67@yahoo.com wrote:

...

Thanks for that Marc. I'm guessing that mdbox format isn't compatible with mail-crypt for the same reasons as mbox. Can anyone confirm? The built in dovecot dsync utility so far looks much more promising. I have about 20 users consuming less than 50GB of email storage. I tend to doubt on a good sized Linux server I will run into storage issues or run out of inodes.

For those still following along, mb2md didn't seem to work well for me. It lost or corrupted enough email that I gave up on it. Less than 1%, but still too high. --Doug

Marc wrote: What you should also consider if you are using some distributed filesystem or block devices, is that maildir format created lots of small files, which in some storage backends will give you quite a bit of storage amplification. That is why I choose for the mdbox format.

On Friday, February 11, 2022, 05:02:25 PM EST,cincodemayo_67@yahoo.com  <cincodemayo_67@yahoo.com>  wrote:

Agreed I am looking to migrate in place, if I migrate at all. I'm still researching the benefits (aside from mail-encrypt) to using Maildir instead. It may be the new default, but to me it is an unknown. I am going to play with the mb2md utility (https://centos.pkgs.org/7/epel-x86_64/mb2md-3.20-17.el7.noarch.rpm.html) in a test instance to see if migrating in place is a feasible.

Thanks for your responses, very much appreciated.

On Friday, February 11, 2022, 03:57:39 PM EST, John Stoffel<john@stoffel.org>  wrote:

Unfortunately, this document doesn't really address the OP's need, which is to migrate mailbox formats on the same server.  Now migrating to a new server would work, where the new server was setup to use maildir as the default.

Maybe a new section could be added talking about this situation in more explicit terms, with some real examples of conversions?

John

Aki>https://doc.dovecot.org/admin_manual/migrating_mailboxes/

Aki> Aki

...

...

On 11/02/2022 21:29cincodemayo_67@yahoo.com cincodemayo_67@yahoo.com wrote:

Thank you for confirming. That was the conclusion I came to, particularly after seeing the structure of Maildir mailboxes and how the individual messages were encrypted. Clearly it would be difficult to do the same with an unlimited number of messages stored in a single file.

A followup question if I may. I probably should just start another thread, but, how difficult is it to convert to Maildir? Any gotchas? Any differences in how to manage the server? How effective is the mb2md? Not looking for a cookbook, just an opinion on whether it is worth converting.

We've used mbox format going back before CentOS 5, so change is hard.

Environment is CentOS 7, Dovecot, Sendmail, Pigeonhole, MailScanner, Mailwatch SQL, Thunderbird clients.

Thanks, Doug On Friday, February 11, 2022, 09:31:09 AM EST, Aki Tuomiaki.tuomi@open-xchange.com wrote:

...

On 11/02/2022 16:26cincodemayo_67@yahoo.com cincodemayo_67@yahoo.com wrote:

Hi,

My Dovecot server of many years has been set up to use mbox email folders. I want to implement mail-crypt and after banging my head against a wall for a few days trying to get mail-crypt to work I decided to try it against a test instance of my server that I reset to use Maildir format and mail-crypt worked instantly.

Does mail-crypt work with mbox format mail folders, or am I wasting my time unless I switch over to Maildir? The documentation athttps://doc.dovecot.org/configuration_manual/mail_crypt_plugin/ doesn't explicitly say Maildir is required.

Thanks in advance,

Doug

Mail crypt will not work with it. Mbox format has limited support of features.

Aki Tuomi