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
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Wed, 27 Jan 2016, voytek at 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 linkwhich 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 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEVAwUBVqhkEnz1H7kL/d9rAQITVAgAm72Db7j5LVthaXVBC9zsKNn+IYeJY43a Yjz6KIjxyJxj+YSsZdemE+HekLX6i3k1GjHWyDVrbeaGaatS0PanpN1BMi15hJUQ 01YRNS8N2rZRh1HJmjajAIzRyN30Pg5VIBvtvgy4PZZjCpTX7xd9U924pYQUpId4 NzwupRqVdBTr5kGbDOA9f9ctSN9TXRR5o4kn/2dX6eCjCDMuXoK4vcLtK8h9Y+iC /qqcpYvi5B1JuwffSNps/RxqDZbSQeLbJDqE7bR3CGR/1/MC5bLQoi1afegUAT67 x1APsJ1FtVdQiBc3oeVg13XmLG2obuowg4etOT+cpdIIiW/Zyun31A==pNSM -----END PGP SIGNATURE-----
Den 27. jan. 2016 07:30, skrev Steffen Kaiser:> On Wed, 27 Jan 2016, voytek at 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) .
On 01/27/2016 03:35 AM, voytek at 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, VYour 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 -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: OpenPGP digital signature URL: <http://dovecot.org/pipermail/dovecot/attachments/20160127/35de1b30/attachment-0001.sig>
On 27/01/16 04:35, voytek at 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
On 1/27/2016 1:30 AM, Steffen Kaiser <skdovecot at smail.inf.fh-brs.de> 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.