dovecot - Mar 2013 - Disallow POP3 from deleting messages

I'd like to use Dovecot as our IMAP server when our users are within our
LAN, but I'd also like to give them the ability to access their emails via
POP3 when they are outside the LAN.  I know most POP3 clients will give their
users the option of not deleting the messages from the server after they are
downloaded, but is there any way to restrict them from being able to do so at
the server level?

In other words, I want to disallow the server from accepting the DELE command
from POP3 clients.

Is that possible?

We have some accounts that multiple users need simultaneous access to.  I
don't want a user to decide to set up a POP3 account on his own on his iPad
or something, and inadvertently blow the Inbox away for everybody else.

We have a satellite connection, so our upload speeds are real slow.  I think
POP3 would give a lot better user experience than IMAP when they are outside the
LAN.

Any help or advice will be greatly appreciated.

Peter, hieromonk

----
Dormition Skete
 Monastery Website:  http://www.DormitionSkete.org
 Convent Website:  http://www.HolyApostlesConvent.org
----

On Wed, 2013-03-20 at 06:39 -0600, DormitionSkete at hotmail.com
wrote:
> I'd like to use Dovecot as our IMAP server when our users are within
our LAN, but I'd also like to give them the ability to access their emails
via POP3 when they are outside the LAN.  I know most POP3 clients will give
their users the option of not deleting the messages from the server after they
are downloaded, but is there any way to restrict them from being able to do so
at the server level?
> 
> In other words, I want to disallow the server from accepting the DELE
command from POP3 clients.
> 
> Is that possible?
You could create a (global) ACL to not allow user to delete own mails.
But some clients will probably keep redownloading the same mails over
and over again then.

Am 20.03.2013 13:39, schrieb DormitionSkete at
hotmail.com:
> I'd like to use Dovecot as our IMAP server when our users are within
our LAN, but I'd also like to give them the ability to access their emails
via POP3 when they are outside the LAN.  I know most POP3 clients will give
their users the option of not deleting the messages from the server after they
are downloaded, but is there any way to restrict them from being able to do so
at the server level?
> 
> In other words, I want to disallow the server from accepting the DELE
command from POP3 clients.
> 
> Is that possible?
> 
> We have some accounts that multiple users need simultaneous access to.  I
don't want a user to decide to set up a POP3 account on his own on his iPad
or something, and inadvertently blow the Inbox away for everybody else.
> 
> We have a satellite connection, so our upload speeds are real slow.  I
think POP3 would give a lot better user experience than IMAP when they are
outside the LAN.
> 
> Any help or advice will be greatly appreciated.
> 
> Peter, hieromonk
> 
> ----
> Dormition Skete
>  Monastery Website:  http://www.DormitionSkete.org
>  Convent Website:  http://www.HolyApostlesConvent.org
> ---- 
> 
> 
> 
dont think this is possible, but you may redirect mails to subfolder (
filter for big mails ) with i.e. sieve and exclude the subfolder from
pop3 sight
i blogged some example with virtual plugin, sorry german and not exactly
what you asked for, its for auto sort spam mail , but perhaps it gives
you an idea how solve your problem

for the whole situation , why not simple allow only imap , and perhaps
use folder acl etc , downloading only subjects first  or some special
folders etc to save bandwith should be possible with most mobile clients

http://sys4.de/de/blog/2013/02/11/dovecot-virtual-setup-mit-globaler-sieve-spamfilter-regel-fur-pop3-nutzer/


Best Regards
MfG Robert Schetterer

-- 
[*] sys4 AG

http://sys4.de, +49 (89) 30 90 46 64
Franziskanerstra?e 15, 81669 M?nchen

Sitz der Gesellschaft: M?nchen, Amtsgericht M?nchen: HRB 199263
Vorstand: Patrick Ben Koetter, Axel von der Ohe, Marc Schiffbauer
Aufsichtsratsvorsitzender: Joerg Heidrich

On Mar 20, 2013, at 7:22 AM, Thomas Leuxner wrote:
> * DormitionSkete at hotmail.com <dormitionskete at hotmail.com>
2013.03.20 14:17:
> 
>> Everybody here uses Macs, iPads or iPhones. We would not necessarily
have to support a wide variety of clients.
> 
> Their Mail Clients natively support IMAP, so not sure why you would want to
go with POP3 in this scenario.

Well, like I said, we have real slow upload speeds.  I think POP3 would give a
better user experience.

* DormitionSkete at hotmail.com <dormitionskete at hotmail.com> 2013.03.20
14:35:
> > Their Mail Clients natively support IMAP, so not sure why you would
want to go with POP3 in this scenario.
> 
> 
> Well, like I said, we have real slow upload speeds.  I think POP3 would
give a better user experience.
The clients mentioned will cache the messages locally. They will download
headers first while they will retrieve the rest in the background. iOS Devices
will even apply thresholds on larger messages downloading them partly and
completing the rest upon request.

Regards
Thomas
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