Nekada se ne može (potpuno) isprazniti Trash folder. Provereno rešenje je:
“Backup your evolution data using the “file->backup settings” option.
Go to your home folder.
Check the “show hidden files” in the view menu to see all the files.
Navigate to “.evolution/mail/local” folder. select and DELETE all files with the following extensions:
.index
.ev-summary
.cmeta
Do NOT delete the files ending in “.data”
Restart evolution. Give it a few minutes to load as it will have to re-create all the indices.
You should now be able to delete files from trash and junk.”
http://ubuntuforums.org/showthread.php?t=974536