#363 Large volume Data - Refetching Mails

[Christoph Schneider]

I have the problem that in an environment with Exchange Server and Davmail (Client Mailmate OSX) the folders are constantly refetched. So I get an average of 2-4 TB of data per day. Does anyone else have the problem or can help me?

[Christoph Schneider]

It looks like a folder (e.g. Sent) is being completely re-fetched as soon as it receives a new mail or moved to folder. Ist this norma? Does not make sense with my approx. 30 GB mailbox...

[Mickael Guessant]

This is probably related to Mailmate IMAP implementation: if DavMail is unable to detect header fetch request it will download all messages content on fetch.

Quick workaround: enable imapAlwaysApproxMsgSize in DavMail settings
(Use Exchange message size).

Long answer: Exchange does not have exact MIME message size, only an approximate size => the only way to get exact message size is to download full MIME message content.

As some IMAP clients (e.g. mutt) are very sensitive to RFC822.SIZE value, this is the default behaviour. However we also have special cases for common IMAP clients to send Exchange message (approximate value) in RFC822.SIZE.

If you provide an example fetch sequence with Mailmate I may be able to improve this.

[Christoph Schneider]

Hi Mickael,

thanks for your answer for now. I had already activated the option, unfortunately without success. Here are a logfiles and the properties.

Regards
Christoph

[Mickael Guessant]

Ok, nothing obviously wrong in your log files, except that you have very large folders.
=> the only way to reduce bandwith is to limit folder size in DavMail settings.

More context info: there is no way from DavMail to know if someone else changed folder content
=> on any ctag change on a folder DavMail has to reload full message list with basic flags.
With large folders (>5k messages) this can be very slow.

[Christoph Schneider]

Hi Mickael,

thanks for the quick answer. I set the folder limit to 100. Is it correct that only 100 mails, even partially less in the folders are present. Thought the already snychronised mails remain and it is only about changes in the folders. So this is for me unfortunately not practicable since I also have to access many mails again and again.
I ask Benny from Mailmate agin if he had a soultion for that.

What Clients davmail with Exchange are preffered for a stable (Bandwith) enviroment under Mac OS?

Best Regards
Christoph

[Christoph Schneider]

Hi Mikael,

Benny from Mailmate ask when davmail exactly change the UIDVALIDITY value of a mailbox.

[Mickael Guessant]

Never, UIDVALIDITY is always 1.

[Christoph Schneider]

I have now downloaded 95 GB via Davmail in 4 days. Unfortunately this is not a permanent state, others should have problems too, or are there clients with Davmail that don't have these problems?

[Mickael Guessant]

According to user feedback most users have Thunderbird, others use OSX Mail.app, mutt or Emacs. We also have Android and iOS users on the mobile side.

Anyway 95GB seem huge, is there any way in Mailmate to limit folder sync ?