After a system freeze, evolution ceased to be able to generate the folder list for my inbox. The statusbar said Error While Generating message list. Clicking on the message popped up this dialog:
According to this bug report the issue might be linked to evolutions use of SQLite.
In the same bug report it was suggested that the following command might solve the issue.
cd ~/.evolution/mail ; for i in `find . -name folders.db`; do echo "Rebuilding Table $i"; sqlite3 $i "pragma integrity_check;"; done
I didn’t have sqlite3 installed, so I ran sudo apt-get install sqlite3 first. For me this command located a handful of files called folders.db and sqlite3 did find errors in one of them: ~/.evolution/mail/local/folders.db.
To make sure that I had the right file I ran
sqlite3 ~/.evolution/mail/local/folders.db "pragma integrity_check;"
which again presented the errors. In the bug report someone explained that missing folder.db files would be regenerated, so I tried stopping all evolution-related processes (evolution-data-server and evolution-alarm-notify will linger after exitting the main program) and removed the file. I then started evolution and everything came up nicely.