Comment 6 for bug 1312888

I was able to get Evolution working again after doing the following:

- I added the Gnome PPA to install the Gnome 3.10 items that didn't make it into 14.04. In my haste, I forgot to jot down what was added to validate any packages that may have fixed Evolution. I was running Ubuntu (Unity) 14.04 with just Evolution installed by itself.
     - sudo add-apt-repository ppa:gnome3-team/gnome3
     - sudo apt-get update && sudo apt-get dist-upgrade
     -restart

- When you launch Evolution after the reboot, the problem will either still be there, you will be constantly prompted for your credentials, or Evolution will somehow think you're offline and will not connect to the mailbox (despite Evolution being online).

- Remove the following directory to remove all personal Evolution configuration files
     - rm -rf ~/.config/evolution

- Re-add your EWS account via the online accounts dialog or launch Evolution to go through the setup Wizard.

Once you do that, you should be able to use Evolution normally. We still need to determine root cause but at least we have a work around...