How to use dovecot only as POP3 server / prevent it from creating .imap directories?
Dear all,
on our mail server, I let sendmail deliver incoming messages to a file in mbox format called "inbox" in each user's home directory. Now I would like to use dovecot as POP3 server so that users can let their MUA download their messages via POP3. I do not want to use any IMAP functionality.
The POP3 part works with the configuration shown below, but nevertheless there is a problem which is a show stopper:
Although I think I have turned off IMAP (e.g. no IMAP listener), dovecot still creates .imap directories and does so in a very weird way. It creates one .imap subdirectory in every subdirectory of each user's home directory, and for every file in each user's home directory creates an additional subdirectory with the same name in its .imap directories. It does this recursively, and 1000 files in a user's home directory would mean 1000 additional subdirectories.
Of course, I can't live with that. I know that the dovecot documentation discourages using the home directory as mail location, but in my case this should not be a problem at all if IMAP is not used. I have played around with dovecot for several days, but could not solve that problem.
So how can I turn off IMAP completely and prevent dovecot from creating any .imap directories or IMAP related files?
This happens with dovecot 2.3.4.1 (f79e8e7e4) on Debian buster (with all updates applied).
My configuration (doveconf -n) is (the configuration is complete - I don't use SQL or LDAP):
# 2.3.4.1 (f79e8e7e4): /etc/dovecot/dovecot.conf # Pigeonhole version 0.5.4 () # OS: Linux 4.19.0-9-amd64 x86_64 Debian 10.4 # Hostname: host.example.com listen = aaa.bbb.ccc.ddd mail_location = mbox:~:INBOX=~/inbox mail_privileged_group = mail namespace inbox { inbox = yes location = mailbox Drafts { special_use = \Drafts } mailbox Junk { special_use = \Junk } mailbox Sent { special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { special_use = \Trash } prefix = } passdb { driver = pam } pop3_lock_session = yes protocols = " pop3" service imap-login { inet_listener imap { port = 0 } inet_listener imaps { port = 0 } } service pop3-login { inet_listener pop3 { port = 0 } inet_listener pop3s { port = 995 ssl = yes } } ssl = required ssl_cert =
Thank you very much in advance for any idea!
Regards,
Binarus
On Sun, Jun 07, 2020 at 08:44:51AM +0200, Binarus wrote:
Dear all,
on our mail server, I let sendmail deliver incoming messages to a file in mbox format called "inbox" in each user's home directory. Now I would like to use dovecot as POP3 server so that users can let their MUA download their messages via POP3. I do not want to use any IMAP functionality.
The POP3 part works with the configuration shown below, but nevertheless there is a problem which is a show stopper:
Although I think I have turned off IMAP (e.g. no IMAP listener), dovecot still creates .imap directories and does so in a very weird way. It creates one .imap subdirectory in every subdirectory of each user's home directory, and for every file in each user's home directory creates an additional subdirectory with the same name in its .imap directories. It does this recursively, and 1000 files in a user's home directory would mean 1000 additional subdirectories.
Of course, I can't live with that. I know that the dovecot documentation discourages using the home directory as mail location, but in my case this should not be a problem at all if IMAP is not used. I have played around with dovecot for several days, but could not solve that problem.
So how can I turn off IMAP completely and prevent dovecot from creating any .imap directories or IMAP related files?
I suppose you'd be OK with having IMAP but having it look *only* at the designated mbox file.
That would be something I could use.
-- hendrik
This happens with dovecot 2.3.4.1 (f79e8e7e4) on Debian buster (with all updates applied).
My configuration (doveconf -n) is (the configuration is complete - I don't use SQL or LDAP):
# 2.3.4.1 (f79e8e7e4): /etc/dovecot/dovecot.conf # Pigeonhole version 0.5.4 () # OS: Linux 4.19.0-9-amd64 x86_64 Debian 10.4 # Hostname: host.example.com listen = aaa.bbb.ccc.ddd mail_location = mbox:~:INBOX=~/inbox mail_privileged_group = mail namespace inbox { inbox = yes location = mailbox Drafts { special_use = \Drafts } mailbox Junk { special_use = \Junk } mailbox Sent { special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { special_use = \Trash } prefix = } passdb { driver = pam } pop3_lock_session = yes protocols = " pop3" service imap-login { inet_listener imap { port = 0 } inet_listener imaps { port = 0 } } service pop3-login { inet_listener pop3 { port = 0 } inet_listener pop3s { port = 995 ssl = yes } } ssl = required ssl_cert =
Thank you very much in advance for any idea!
Regards,
Binarus
On 07.06.2020 17:56, Hendrik Boom wrote:
On Sun, Jun 07, 2020 at 08:44:51AM +0200, Binarus wrote:
Dear all,
on our mail server, I let sendmail deliver incoming messages to a file in mbox format called "inbox" in each user's home directory. Now I would like to use dovecot as POP3 server so that users can let their MUA download their messages via POP3. I do not want to use any IMAP functionality.
The POP3 part works with the configuration shown below, but nevertheless there is a problem which is a show stopper:
Although I think I have turned off IMAP (e.g. no IMAP listener), dovecot still creates .imap directories and does so in a very weird way. It creates one .imap subdirectory in every subdirectory of each user's home directory, and for every file in each user's home directory creates an additional subdirectory with the same name in its .imap directories. It does this recursively, and 1000 files in a user's home directory would mean 1000 additional subdirectories.
Of course, I can't live with that. I know that the dovecot documentation discourages using the home directory as mail location, but in my case this should not be a problem at all if IMAP is not used. I have played around with dovecot for several days, but could not solve that problem.
So how can I turn off IMAP completely and prevent dovecot from creating any .imap directories or IMAP related files?
I suppose you'd be OK with having IMAP but having it look *only* at the designated mbox file.
That would be something I could use.
Thank you very much for your comment. You are completely right - I could very well live with that solution.
However, I have researched for many hours before posting here, but I could not find out how to achieve this. As I have described in my first post, dovecot created an .imap subdirectory in each directory which existed, and created one subdirectory (within the .imap directory) for each file which existed, and it did so recursively. Whatever portions in the configuration files I commented out, and whatever service I disabled by other means (e.g. by giving Port = 0), I could not prevent dovecot from messing up users' home directories completely, i.e. I could not make it use only the mbox file and leave the directories as-is otherwise (possibly adding a file or two for management and housekeeping).
This is extremely weird and not acceptable; imagine 10,000 directories being created for nothing solely because there are 10,000 files. Plus, it is a behaviour which previous versions did not show (I have pulled over the configuration from another system running Debian jessie, where the problem did not arise). I still can't understand why it does IMAP things at all, given that I have protocols = " pop3".
So how exactly do I have to alter the configuration to implement your suggestion, i.e. to make dovecot look only at the mbox file and to prevent the creation of unnecessary directories?
Thank you very much again,
Binarus
On Sun, 7 Jun 2020, Binarus wrote:
So how exactly do I have to alter the configuration to implement your suggestion, i.e. to make dovecot look only at the mbox file and to prevent the creation of unnecessary directories?
Maybe try
mail_location = mbox:/empty/dir:INBOX=~/inboxNot sure whether owner=rootZ:root, mode=555 will work, but those permissions would be the safest.
Joseph Tam jtam.home@gmail.com
On 08.06.2020 07:41, Joseph Tam wrote:
On Sun, 7 Jun 2020, Binarus wrote:
So how exactly do I have to alter the configuration to implement your suggestion, i.e. to make dovecot look only at the mbox file and to prevent the creation of unnecessary directories?
Maybe try
mail_location = mbox:/empty/dir:INBOX=~/inbox
Not sure whether owner=rootZ:root, mode=555 will work, but those permissions would be the safest.
Thank you very much for your suggestion. Actually, I already had tried that, but that was only for testing, and I was hoping to avoid it.
Having said this:
That suggestion does not solve the problem completely, but reduces the negative impact so much that I can live with it. I had tried
mail_location = mbox:~/mail:INBOX=~/mail/inbox
With that, dovecot still created an .imap subdirectory, but only within the mail subdirectory in every user's home directory. The layout was the following (starting in an arbitrary user's home directory, showing only the contents of the mail subdirectory):
./mail/inbox ./mail/.imap ./mail/.imap/dovecot-uidvalidity ./mail/.imap/dovecot.list.index.log ./mail/.imap/dovecot-uidvalidity.5edce848 ./mail/.imap/INBOX ./mail/.imap/INBOX/dovecot.index.log ./mail/.imap/INBOX/dovecot.index ./mail/.imap/INBOX/dovecot.index.log.2 ./mail/.imap/INBOX/dovecot.index.cache
While there are no .imap subdirectories in other parts of the home directories any more (which was the main goal), there are still at least three unnecessary files plus one unnecessary directory with four unnecessary files left. This is an ugly waste of resources, but it won't keep me from going that way.
Obviously, dovecot is not meant to serve only POP3 any more (it used to work in previous versions, where it didn't create .imap directories if IMAP was disabled, if I remember correctly), but I don't know an alternative. All other POP3 servers which are currently maintained which I am aware of also have included an IMAP part, so I can probably expect the same problems as with dovecot. Since I currently have no motivation to learn another server software's configuration just to see that this got me nowhere, I'll just stick with the solution outlined above and hope that the POP3 part of dovecot will not be given up in the next versions, and that dovecot does not go wild and start to create more and more directories or files in unforeseeable manner.
The disadvantage of the solution above was that I had to reconfigure the MTA (in this case, sendmail) to deliver inbound messages to ~/mail/inbox instead of ~/inbox, which is another why I didn't implement this solution immediately. At least, this was quite easy.
Thank you very much again!
Regards,
Binarus
On Tue, Jun 09, 2020 at 12:32:18 +0200, Binarus wrote: ...
./mail/inbox ./mail/.imap ./mail/.imap/dovecot-uidvalidity ./mail/.imap/dovecot.list.index.log ./mail/.imap/dovecot-uidvalidity.5edce848 ./mail/.imap/INBOX ./mail/.imap/INBOX/dovecot.index.log ./mail/.imap/INBOX/dovecot.index ./mail/.imap/INBOX/dovecot.index.log.2 ./mail/.imap/INBOX/dovecot.index.cache
While there are no .imap subdirectories in other parts of the home directories any more (which was the main goal), there are still at least three unnecessary files plus one unnecessary directory with four unnecessary files left. This is an ugly waste of resources, but it won't keep me from going that way.
Obviously, dovecot is not meant to serve only POP3 any more
The .imap directory isn't really about IMAP. It is sort of a generic directory that just happens to have "imap" in the name. The index files you see are required for various features inside dovecot to work properly. Many of them are related to performance rather than a specific protocol. Granted, POP3 is such a simple protocol that most of the features don't apply to a POP3-only server.
If you don't want the index files to live inside the users' home directories, take a look at the INDEX and CONTROL keys in the mail_location docs:
https://doc.dovecot.org/configuration_manual/mail_location/#format
While that still creates the files, you can move them off to a location that the users do not see.
Jeff.
On Wed, 17 Jun 2020, Josef 'Jeff' Sipek wrote:
On Tue, Jun 09, 2020 at 12:32:18 +0200, Binarus wrote: ...
./mail/inbox ./mail/.imap ./mail/.imap/dovecot-uidvalidity ./mail/.imap/dovecot.list.index.log ./mail/.imap/dovecot-uidvalidity.5edce848 ./mail/.imap/INBOX ./mail/.imap/INBOX/dovecot.index.log ./mail/.imap/INBOX/dovecot.index ./mail/.imap/INBOX/dovecot.index.log.2 ./mail/.imap/INBOX/dovecot.index.cache
The .imap directory isn't really about IMAP. It is sort of a generic directory that just happens to have "imap" in the name. The index files you see are required for various features inside dovecot to work properly. Many of them are related to performance rather than a specific protocol.
Spot on.
If you don't want the index files to live inside the users' home directories, take a look at the INDEX and CONTROL keys in the mail_location docs:
https://doc.dovecot.org/configuration_manual/mail_location/#format
While that still creates the files, you can move them off to a location that the users do not see.
Or you can create in-memory indices, but that is a solution to the wrong problem.
By specifically stating in mail_location that ~user holds mailboxes, you are telling Dovecot an untruth. It's better to tell Dovecot user mailboxes (other than INBOX) don't exist, rather than to push all the indices under the carpet.
Joseph Tam jtam.home@gmail.com
On 19.06.2020 00:27, Joseph Tam wrote:
On Wed, 17 Jun 2020, Josef 'Jeff' Sipek wrote:
On Tue, Jun 09, 2020 at 12:32:18 +0200, Binarus wrote: ...
./mail/inbox ./mail/.imap ./mail/.imap/dovecot-uidvalidity ./mail/.imap/dovecot.list.index.log ./mail/.imap/dovecot-uidvalidity.5edce848 ./mail/.imap/INBOX ./mail/.imap/INBOX/dovecot.index.log ./mail/.imap/INBOX/dovecot.index ./mail/.imap/INBOX/dovecot.index.log.2 ./mail/.imap/INBOX/dovecot.index.cache
The .imap directory isn't really about IMAP. It is sort of a generic directory that just happens to have "imap" in the name. The index files you see are required for various features inside dovecot to work properly. Many of them are related to performance rather than a specific protocol.
Spot on.
If you don't want the index files to live inside the users' home directories, take a look at the INDEX and CONTROL keys in the mail_location docs:
https://doc.dovecot.org/configuration_manual/mail_location/#format
While that still creates the files, you can move them off to a location that the users do not see.
Or you can create in-memory indices, but that is a solution to the wrong problem.
By specifically stating in mail_location that ~user holds mailboxes, you are telling Dovecot an untruth. It's better to tell Dovecot user mailboxes (other than INBOX) don't exist, rather than to push all the indices under the carpet.
I just noticed that I haven't said thank you yet.
However, the solution I have implemented works very nice since several months now, so I currently don't plan to change or improve anything.
Thanks again, and best regards,
Binarus
On 17.06.2020 17:41, Josef 'Jeff' Sipek wrote:
On Tue, Jun 09, 2020 at 12:32:18 +0200, Binarus wrote: ...
./mail/inbox ./mail/.imap ./mail/.imap/dovecot-uidvalidity ./mail/.imap/dovecot.list.index.log ./mail/.imap/dovecot-uidvalidity.5edce848 ./mail/.imap/INBOX ./mail/.imap/INBOX/dovecot.index.log ./mail/.imap/INBOX/dovecot.index ./mail/.imap/INBOX/dovecot.index.log.2 ./mail/.imap/INBOX/dovecot.index.cache
While there are no .imap subdirectories in other parts of the home directories any more (which was the main goal), there are still at least three unnecessary files plus one unnecessary directory with four unnecessary files left. This is an ugly waste of resources, but it won't keep me from going that way.
Obviously, dovecot is not meant to serve only POP3 any more
The .imap directory isn't really about IMAP. It is sort of a generic directory that just happens to have "imap" in the name. The index files you see are required for various features inside dovecot to work properly. Many of them are related to performance rather than a specific protocol. Granted, POP3 is such a simple protocol that most of the features don't apply to a POP3-only server.
If you don't want the index files to live inside the users' home directories, take a look at the INDEX and CONTROL keys in the mail_location docs:
https://doc.dovecot.org/configuration_manual/mail_location/#format
While that still creates the files, you can move them off to a location that the users do not see.
Jeff.
A little bit late, but just wanted to thank you for your explanation.
By the way, that solution is playing very well in practice - no reason to change or improve something.
Thanks again, and best regards,
Binarus
participants (4)
-
Binarus
-
Hendrik Boom
-
Josef 'Jeff' Sipek
-
Joseph Tam