Incomplete sync using imap with groupwise 2014 mailserver

[Mathias]

Device: Samsung Note 10.1 with Android 5.1 and Aquamail pro
Language: German
Push is not supported by the server.
The error occurred first in other email apps (including K9, Bluemail, Gmail) I used before I changed to Aqua. These apps have been uninstalled before I started with Aqua. Gmail and Samsung email can not be uninstalled.
Did a fresh installation  of Aquamail and Imap account to the universities groupwise server, using default values for all options. The folder structure of the server is automatically  associated correctly.
The inbox (containing 2700 mails from the last 18 months) is syncronised only until 29. February 2016. New Mails don't appear in Aquamail. All other folders are completely synchronised.
Thunderbird on Windows works correctly with the Mailbox.
The error occurs with all tested email apps on this device, but only Aquamail allowes for the following:
When I change the sync from the default of 50 mails to 30 days, the inbox is syncronised completely. This looks great, but unfortunately now the sent mails folder (containing ~1500 mails) is now not syncronised correctly. Only the mails sent with Aquamail appear, and some but not all mails sent with other mailapps fron the android device. Mails sent from other computers after 15. February don't appear in Aquamail. All mails sent from whatever before 15. February are syncronised completely.
The error is reproducible. I can decide wether I want a complete inbox or a complete sent folder.

The mailserver admin was not able to help me. I could not find anybody else having this type of problem. Do you have any idea?

Mathias

[Kostya Vasilyev]

Since you're seeing all kinds of weirdness with other apps -- even though the exact details are different -- I *strongly* suspect that this is a server issue.

Re: syncronised only until 29. February 2016

This means that the messages on the server are not ordered by date (in terms UID's / sequence numbers, those are both IMAP terms, with exact definitions).

IMAP *requires* this for incoming messages, can only change if you move a lot of messages between folders, or if there is a server issue.

Even if you moved messages, any messages *received* after that should show in AquaMail.

And so I suspect a second issue too: the folder's message count is not correctly reported from the SELECT command (standard IMAP command).

Re: now the sent mails folder (containing ~1500 mails) is now not syncronised correctly

And this means that the server is not returning any messages when the app asks for "messages received since 30 days" (or whatever).

Now, Sent messages are of course not received, but they should have their "received date/time" (called INTERNALDATE in IMAP) set too, to the "when a message was sent".

So this is server issue #2 (maybe #3).

What you may want to do is: long press the account -> options and folders -> IMAP options -> change "which date/time to download" from "server time (received)" to "date header (sent)".

And then refresh the account.

Hopefully the server properly implements "search by Date header" (which Sent messages definitely do have), but I can't know if it does.

Re: Thunderbird

A desktop mail app can afford to load "everything", their sync algorithms are much more basic, they just ask the server for "all messages" and download them all.

So they (desktop mail apps) are fortunate to not be affected by any of these issues.

( but I wish Thunderbird has a setting to only sync some number of recent messages, not "everything"... alas... )

[Mathias]

Thank you! It syncs completely with 30 days and your advice

What you may want to do is: long press the account -> options and folders -> IMAP options -> change "which date/time to download" from "server time (received)" to "date header (sent)".

Sync 50 mails does not work.
I'll forward this topic to my email admin and post his answer if it contains any interesting facts

[Kostya Vasilyev]

I meant: sync by date range + "date header (sent)".

With "sync by date range" + "date received" (the default) -- the app searches messages by "date range, where date means received", or INTERNALDATE in IMAP terms.

With "sync by date range" + "date sent" (the change I'm suggesting) -- the app searches by "date range, where date means Date header", this might work for sent messages.

[Mathias]

Yes, I understood.  "sync by date range" worked already  for incoming mail and "sync by date range" + "date sent" does it for both incoming and sent mail.