Comment 4 for bug 247396

You *did* enable the tnef-attachment extension, right?

Another thing might be going on: check if you have libytnef0 installed. For example, on a terminal, type 'dpkg -l libytnef\*'. You should see something like:

hggdh@xango2:~/.evolution $ dpkg -l libytnef\*
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Cfg-files/Unpacked/Failed-cfg/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: uppercase=bad)
||/ Name Version Description
+++-===========================-===========================-======================================================================
un libytnef-dev <none> (no description available)
ii libytnef0 1.5-1 improved decoder for application/ms-tnef attachments
ii libytnef0-dev 1.5-1 improved decoder for application/ms-tnef attachments
hggdh@xango2:~/.evolution $

libytnef0 has status 'ii', this is good. If you see it with *any* other status, then, from the terminal, issue:

sudo apt-get install libytnef0

then bounce Evolution again. You should now be all set.