POP3 server side retention

Discuss your pilot or production implementation with other Zimbra admins or our engineers.
Posts: 45
Joined: Sat Sep 13, 2014 2:25 am
ZCS/ZD Version: Release 8.8.8_GA_2009.RHEL7_64_2018

POP3 server side retention

Postby stasouv » Wed Nov 28, 2012 5:07 am

Hello everyone,
I'm quite certain that such a possibility does not exist, but I'll ask anyway, just in case it's useful...
We currently lack resources to keep full snapshots (or backups) of our user data. Thus, it's (currently) impossible to rollback a single mailbox to a previous state. We do have storage running in failover, so we count on that for integrity.
Our main issue has arisen from an accidental deletion of inbox contents through misconfigured POP3 account... All messages were downladed from server w/out keeping a copy and then purged from the client... Accident we've been told, but not quite recuperable...
So here comes the question, which in my imagination combines dumpster and retention policy.
Is there (or will there be) the possibility to instruct the server to flag messages for deletion that have been fetched through pop3 protocol but no copy is set to be kept on server (but not acutally delete them yet) and have them deleted after X days or something like that? In such a case, it would be imperative to be able to recover those messages, of course...
Zimbra Version is

Release 8.0.0.GA.5434.UBUNTU10.64 UBUNTU10_64 FOSS edition.
Thanks for your time.

PS: I'd like to clear out that I'm not talking about the client configuration option to leave o copy on the server... I'm talking about server configuration, to retain messages (invisibly to users) that are to be deleted from server due to pop3 client request.

Advanced member
Advanced member
Posts: 157
Joined: Sat Sep 13, 2014 2:59 am

POP3 server side retention

Postby 15337Raunaq » Wed Nov 28, 2012 10:55 pm

Hi mate,
What i understand from your post is that you want a dumpster retention policy which is already there in zimbra 8

You can configure retention policies for user account’s email, trash, and junk folders. The basic email retention policy is to set the email, trash and spam message lifetime in the COS or for individual accounts.

You can set up specific retention policies that users can enable for the Inbox and other email folders in their account. Users can also create their own retention policies.

You can enable the dumpster feature to save messages that are deleted from Trash. When an message lifetime has been reached based on email lifetime rules or deletion policies, the message is moved to the dumpster if it is enabled. Users can recover deleted items from the dumpster until the threshold set in the Visibility lifetime in dumpster for end user setting. If dumpster is not enabled, messages are purged from the server when the email retention lifetime is reached.

You can also set up a legal hold on an account to prevent message from being deleted .
Hope this helps.
Posts: 45
Joined: Sat Sep 13, 2014 2:25 am
ZCS/ZD Version: Release 8.8.8_GA_2009.RHEL7_64_2018

POP3 server side retention

Postby stasouv » Thu Nov 29, 2012 1:12 am

Good morning,

thank you for your reply. Yes, a form of dumpster is actually what I should need.
However, there are two drawbacks. Supposing the client is configured not to keep a copy on the server:

1. POP3 deletion does not imply moving messages to trash folder, messages are directly purged from the server, and

2. Dumpster folder only works for WEB UI, not even IMAP
I have not yet tried retention policy, but even if it works that's hardly convenient for the following three reasons:

1. It's user modifiable

2. It does not provide rollback functionality.

3. Retention applies to message age and not to transaction timestamp. Dumpster considers date of deletion, not date message has appeared.
Let me state my exact point through a simple example:

- User X has configured a new client for POP3 access, forgetting though to instruct (not default) the server to keep a copy of the message, as he has always done on his clients on other machines.

- He fetches his mail, which is subsequently purged from his mailbox on the server

- His data file (eg .pst, .dbx etc) gets corrupted or his messages are deleted for any reason (even by hand)

- He panics, as his mail is now lost and he requests for a rollback to the previous backup (ZONK!!!!), undoing deletion of his messages.

That's the scenario I'm talking about. And the request is that messages should not be purged from server upon POP3 fetching, but flagged for deletion (visible only to administrator perhaps) and retained for a stated period of time.
I'm probably chasing shadows...
Advanced member
Advanced member
Posts: 83
Joined: Sat Sep 13, 2014 12:36 am

POP3 server side retention

Postby kruon » Thu Nov 29, 2012 1:30 am

[quote user="stasouv"]messages should not be purged from server upon POP3 fetching[/QUOTE]

If you send a postcard via land mail, the post office doesn't keep a copy from it if you lose it after you've received it.
From POP3 RFC1939:

POP3 is not intended to provide extensive manipulation operations of

mail on the server; normally, mail is downloaded and then deleted. A

more advanced (and complex) protocol, IMAP4, is discussed in

Like the RFC says solution is to stop using POP3 and use IMAP instead if you want the mail server to protect stupid users from themselves.

Other obvious option is of course to train your staff/clients and stop assuming they'll figure it out.

If you have people configuring client machines for someone else, provide correct configuration instructions to them so they can perform necessary steps.

That seems stupid to you, but if you have a checklist saying "I selected the option to leave copy of messages to server", then the client is configured like you suggested.
Posts: 45
Joined: Sat Sep 13, 2014 2:25 am
ZCS/ZD Version: Release 8.8.8_GA_2009.RHEL7_64_2018

POP3 server side retention

Postby stasouv » Thu Nov 29, 2012 2:45 am

Thank you kruon,
If you send a postcard via land mail, you don't have it in your outbox either...
I share a lot of your opinion about how users should behave. My interest is "parental" though... Protect them from being stupid... But sometimes I do feel that this is hopeless... Maybe we should consider blocking POP access and imposing IMAP exclusively for clients...
What I ask cannot be done, apparently, so thank you all for your replies.
Posts: 26727
Joined: Fri Sep 12, 2014 9:56 pm
Location: Liverpool, England

POP3 server side retention

Postby phoenix » Thu Nov 29, 2012 4:43 am

[quote user="stasouv"] Maybe we should consider blocking POP access and imposing IMAP exclusively for clients...[/QUOTE]Yes, you should convince your users that this is goping to happen and is a good move. You could also look into implementing some form of archiving solution for your ZCS installation and/or get your users to move to Zimbra Desktop (which has a good backup facility) and train them in using that effectively.


Rspamd: A high performance spamassassin replacement

Per ardua ad astra

Return to “Administrators”

Who is online

Users browsing this forum: No registered users and 13 guests