Version:           2.0.89 (using KDE 4.5.85) 
OS:                Linux

I have used a lot of mail programs over the years and I have moved mails from one system to the other, resulting in almost 50.000 mails. And Kmail2 has some serious problems with this.

First of all - it is unuseable for the first half hour or more after starting. The, if I click on a folder, it reads everything on the harddisk and with this heavy harddisk activity, my computer grinds to a halt. Today it was even so bad that Kubuntu disabled desktop effect automatically in an attempt to minimize the stress on the system.

I thought the whole point of using Akonadi was to get Kmail up to blistering speed... These problems must be temporary - I am living in the hope that there will be a new version out soon that will fix this :-) Speed is essential. And the PIM is one of the biggest reason for me to recommend Kubuntu over Ubuntu. Provided it works.

CPU: Dual core, 2.0 GHz
RAM: 2GB
HD: 320GB SATA, 7200 RPM

Reproducible: Always

Steps to Reproduce:
Start Kontact or Kmail2, check new mail and click on a folder with 8-10.000 messages.

Actual Results:  
Computer harddisk activity goes to max and the computer becomes unresponsive for the next half hour or more.

Expected Results:  
Seeing the list of mails immediately, being able to click on a mail and not having to wait more than a second or two.

This is an absolute showstopper and should be treated as critical. BUT - it does not cause the app to crash. Also, it does not cause dataloss. It just make the app completely unuseable for anyone but the most die hard fans and testers! It should be addresses before anything else as any other testing takes way too much time when the system behaves like this.