Re: ot: data consumption IMAP vs POP

[Charles Marcus]

On 1/27/2016 9:32 AM, Steffen Kaiser  wrote:
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> On Wed, 27 Jan 2016, Charles Marcus wrote:
>
>> On 1/27/2016 1:30 AM, Steffen Kaiser  wrote:
>>> Sending bandwitdh can be reduced by using BCC instead of the IMAP append
>>> to the sent mailbox.
>> Can you elaborate on this?
>>
>> I would have thought that the IMAP Append command would *save* bandwidth
>> (as opposed to having the client save a copy to the Sent folder, thereby
>> uploading the full message a second time).
> This is exactly, what IMAP APPEND does: The client uploads the message via 
> SMTP first and via IMAP a second time.

Oops, you're right...

I was thinking of the SMTP Submission Client service discussed here that
Timo said would be trivial to do (he said it would take a few lines of
code for postfix too, but Wietse seemed amenable to adding it)... I
think it may have been using BURL or something, but I'm not sure...

I'd really love to see this implemented. It would make a huge difference
for anyone who sends a lot of large attachments like we do.

> BTW: There is another annoyance with a limited bandwidth, when you compose 
> a message, MUAs autosave the message into Draft in regular intervals.

Yeah - I usually disable this, and save manually. I generally either
finish and send an email, or start one so I won't forget about something
and immediately save it. I do want these available through IMAP, so I do
still want it saved to the IMAP Drafts folder, otherwise, if I had
bandwidth concerns about this and still wanted continuous auto save, I'd
pint my Drafts to the Local Folders Drafts...

Re: ot: data consumption IMAP vs POP

[Sami Ketola]

On 27/01/16 04:35, voy...@sbt.net.au wrote:

I have a domain with about 50 mailboxes, server is located here in AUS but
most of the users are on a LAN is SEAsia location. They were using POP
(with Thunderbird), I suggested then can use IMAP instead, so they did.

now they are asking;

"Looks like Imap is adding a lot to our internet bandwidth"

I guess they have some bandwidth limitation on their link

I think I can understand that IMAP would increase bandwidth requirement,
didn't expect it to cause 'problems'

is there any optimization or changes I can make to reduce that ?
the b/w limitation are at the client LAN link

any other suggestions ?



When you change from POP3 to IMAP then user agents will redownload all 
messages once.
I can't see any other reason for any significant bandwith increment 
other than that.
Are you sure there really is more bandwith used once the mails have been 
redownloaded?


Sami

Re: ot: data consumption IMAP vs POP

[Daniel Tröder]

On 01/27/2016 03:35 AM, voy...@sbt.net.au wrote:
> I have a domain with about 50 mailboxes, server is located here in AUS but
> most of the users are on a LAN is SEAsia location. They were using POP
> (with Thunderbird), I suggested then can use IMAP instead, so they did.
> 
> now they are asking;
> 
> "Looks like Imap is adding a lot to our internet bandwidth"
> 
> I guess they have some bandwidth limitation on their link
> 
> I think I can understand that IMAP would increase bandwidth requirement,
> didn't expect it to cause 'problems'
> 
> is there any optimization or changes I can make to reduce that ?
> the b/w limitation are at the client LAN link
> 
> any other suggestions ?
> 
> thanks, V

Your users IMAP-clients can (hopefully) be configured to automatically
cache emails once they were downloaded. If that is configured, there
should be no difference in bandwidth usage between POP and IMAP.

Greetings
Daniel



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Re: ot: data consumption IMAP vs POP

[Steffen Kaiser]

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On Wed, 27 Jan 2016, Charles Marcus wrote:


On 1/27/2016 1:30 AM, Steffen Kaiser  wrote:

Sending bandwitdh can be reduced by using BCC instead of the IMAP append
to the sent mailbox.


Can you elaborate on this?

I would have thought that the IMAP Append command would *save* bandwidth
(as opposed to having the client save a copy to the Sent folder, thereby
uploading the full message a second time).


This is exactly, what IMAP APPEND does: The client uploads the message via 
SMTP first and via IMAP a second time.


If you add a BCC recipient to each message, that is placed by SMTP into 
the Sent Folder, and disable the IMAP save, you upload the message just 
once. How you can do this, depends on your SMTP framework. Many people use 
subaddressing or detail:


address+det...@example.org

===

BTW: There is another annoyance with a limited bandwidth, when you compose 
a message, MUAs autosave the message into Draft in regular intervals.


- -- 
Steffen Kaiser

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Re: ot: data consumption IMAP vs POP

[Håkon Alstadheim]

Den 27. jan. 2016 07:30, skrev Steffen Kaiser:
> On Wed, 27 Jan 2016, voy...@sbt.net.au wrote:
>
> > I have a domain with about 50 mailboxes, server is located here in
> AUS but
> > most of the users are on a LAN is SEAsia location. They were using POP
> > (with Thunderbird), I suggested then can use IMAP instead, so they did.
>
> > now they are asking;
>
> > "Looks like Imap is adding a lot to our internet bandwidth"
>
> > I guess they have some bandwidth limitation on their link
>
> which limit(s)?
>
> > I think I can understand that IMAP would increase bandwidth requirement,
> > didn't expect it to cause 'problems'
>
> > is there any optimization or changes I can make to reduce that ?
> > the b/w limitation are at the client LAN link
>
> > any other suggestions ?
>
> Do they have problems more while sending or more while reading or more
> when doing "flagging, moving, deleting"?
>
> Sending bandwitdh can be reduced by using BCC instead of the IMAP
> append to the sent mailbox.
> Reading bandwidth should not change, unless they watch really many
> mailboxes.
>
> -- Steffen Kaiser
... but of course re-configuring mail-client will cause all mail that is
still on the server to be re-down-loaded. Did you specifically ask if
bandwidth problems persisted after the first connections ? Might take
quite a while if there is a lot of mail. Might be "on demand" when
entering a mail-box for the first time. If mail comes pre-sorted into
mail-boxes, watching several mail-boxes for new mail might be a
long-term "pessimization" (opposite of optimization) .

Re: ot: data consumption IMAP vs POP

[Charles Marcus]

On 1/27/2016 1:30 AM, Steffen Kaiser  wrote:
> Sending bandwitdh can be reduced by using BCC instead of the IMAP append 
> to the sent mailbox.

Hi Steffen,

Can you elaborate on this?

I would have thought that the IMAP Append command would *save* bandwidth
(as opposed to having the client save a copy to the Sent folder, thereby
uploading the full message a second time).

I want to revisit this with Timo, because there was supposedly a pretty
simple way that we could achieve the same thing that gmail does - auto
save all sent messages to the designated Sent folder server side,
thereby allowing us to disable the 'Save to Sent' function in the client.

Re: ot: data consumption IMAP vs POP

[Steffen Kaiser]

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On Wed, 27 Jan 2016, voy...@sbt.net.au wrote:


I have a domain with about 50 mailboxes, server is located here in AUS but
most of the users are on a LAN is SEAsia location. They were using POP
(with Thunderbird), I suggested then can use IMAP instead, so they did.

now they are asking;

"Looks like Imap is adding a lot to our internet bandwidth"

I guess they have some bandwidth limitation on their link


which limit(s)?


I think I can understand that IMAP would increase bandwidth requirement,
didn't expect it to cause 'problems'

is there any optimization or changes I can make to reduce that ?
the b/w limitation are at the client LAN link

any other suggestions ?


Do they have problems more while sending or more while reading or more 
when doing "flagging, moving, deleting"?


Sending bandwitdh can be reduced by using BCC instead of the IMAP append 
to the sent mailbox.
Reading bandwidth should not change, unless they watch really many 
mailboxes.


- -- 
Steffen Kaiser

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