> On 26 Jan 2016, at 15:56, Marc Schiffbauer <m at sys4.de> wrote: > > * Sami Ketola schrieb am 23.01.16 um 23:27 Uhr: >> >> >> On 23/01/16 15:33, Robert Schetterer wrote: >>> for multiple advanced imap settings at migration you might use >>> imapsync not dsync Best Regards MfG Robert Schetterer >> Sure but imapsync does not preserve message UID's which means that users >> end up redownloading all their messages or message/UID mismatches will >> happen. > > IIRC that is not true. Some years ago I migrated a server to dovecot and > managed to do it with proper UID migration. No clients were required to > re-download Mail. Nor over IMAP neither POP3.IMAP protocol doesn't have a way for clients to specify UIDs. Especially UIDVALIDITY can't be preserved in any way. IMAP clients don't necessarily make it clearly visible that they're redownloading mails though. With POP3 clients if they use the keep-mails-on-server it pretty much has to redownload mails as duplicates. Unless the UIDL was based on some email headers or such, the POP3 UIDL can't be preserved either.
* Timo Sirainen schrieb am 26.01.16 um 16:00 Uhr:> > > On 26 Jan 2016, at 15:56, Marc Schiffbauer <m at sys4.de> wrote: > > > > * Sami Ketola schrieb am 23.01.16 um 23:27 Uhr: > >> > >> > >> On 23/01/16 15:33, Robert Schetterer wrote: > >>> for multiple advanced imap settings at migration you might use > >>> imapsync not dsync Best Regards MfG Robert Schetterer > >> Sure but imapsync does not preserve message UID's which means that users > >> end up redownloading all their messages or message/UID mismatches will > >> happen. > > > > IIRC that is not true. Some years ago I migrated a server to dovecot and > > managed to do it with proper UID migration. No clients were required to > > re-download Mail. Nor over IMAP neither POP3. > > IMAP protocol doesn't have a way for clients to specify UIDs. > Especially UIDVALIDITY can't be preserved in any way. IMAP clients > don't necessarily make it clearly visible that they're redownloading > mails though. With POP3 clients if they use the keep-mails-on-server > it pretty much has to redownload mails as duplicates. Unless the UIDL > was based on some email headers or such, the POP3 UIDL can't be > preserved either.IDNRC ;-) Then I am pretty sure that I used dsync. Because I AM sure that I had no issues with re-dpwnloadeing and that I had an eye on especially on that. -Marc -- [*] 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, Marc Schiffbauer Aufsichtsratsvorsitzender: Florian Kirstein
Am 26.01.2016 um 16:29 schrieb Marc Schiffbauer:> * Timo Sirainen schrieb am 26.01.16 um 16:00 Uhr: >> >>> On 26 Jan 2016, at 15:56, Marc Schiffbauer <m at sys4.de> wrote: >>> >>> * Sami Ketola schrieb am 23.01.16 um 23:27 Uhr: >>>> >>>> >>>> On 23/01/16 15:33, Robert Schetterer wrote: >>>>> for multiple advanced imap settings at migration you might use >>>>> imapsync not dsync Best Regards MfG Robert Schetterer >>>> Sure but imapsync does not preserve message UID's which means that users >>>> end up redownloading all their messages or message/UID mismatches will >>>> happen. >>> >>> IIRC that is not true. Some years ago I migrated a server to dovecot and >>> managed to do it with proper UID migration. No clients were required to >>> re-download Mail. Nor over IMAP neither POP3. >> >> IMAP protocol doesn't have a way for clients to specify UIDs. >> Especially UIDVALIDITY can't be preserved in any way. IMAP clients >> don't necessarily make it clearly visible that they're redownloading >> mails though. With POP3 clients if they use the keep-mails-on-server >> it pretty much has to redownload mails as duplicates. Unless the UIDL >> was based on some email headers or such, the POP3 UIDL can't be >> preserved either. > > IDNRC ;-) > > Then I am pretty sure that I used dsync. Because I AM sure that I had no > issues with re-dpwnloadeing and that I had an eye on especially on that. >Hi Marc, you used dsync before on your project with success, then we tried it too on the "our" project, that failed ,so we used imapsync we ignored the problem with users pop3 letting their mails on the server or better ,we pre informed them what will happen.> -Marc > >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, Marc Schiffbauer Aufsichtsratsvorsitzender: Florian Kirstein