Please describe the problem:
I am currently using Evo to access an account with a 2 Gbyte inbox. Since the server connection is slow (60kbyte/sec, through vpn tunnel) I would really like to have everything synced for offline usage. At the same time, to sync the entire mail base, I would have to leave the computer on for probably 48 hours in a row. This is not feasible. My only option is to synchronise piecemal. 

Today I let synchronisation run until Evolution indicated that 27% were downloaded. At that point, the local cache of the inbox had some 700 MByte. At that point the VPN connection went away and I quit Evolution (no crash, regular exit). 

After restarting, I was shocked to see that the inbox had now shrunk to 136 Megs. Evolution had obviously thrown 550 Megs away, which had taken hours to download.

I have made some more tests to see if this would repeat itself. At first, things went better and I had hope, that this would have been a temporary hickup. But just now, as I'm writing, the local inbox cache has again shrunk by 250 megs after regularly quitting and restarting the problem

Steps to reproduce:
1. Download mail from a relatively large account
2. Measure disk usage of ~/.evolution/mail/echange and its subfolders
3. Quit the program and restart


Actual results:
As said above, sometime it works, but other times Evolution throws away hundreds of megabytes of mail, thus effectively preventing me from ever successfully completing synchronisation.

Expected results:
Evolution should preserve mail which has been downloaded.

Does this happen every time?
No. But frequently enough to seriously annoy me.

Other information: