Forwarding this from a Fedora bug:
https://bugzilla.redhat.com/show_bug.cgi?id=558646

Description of problem:
Evolution intermittently retrieves incomplete message information from exchange
via MAPI.  Some messages come over without a subject.  usually when this
happens, clicking on the message results in evolution claiming:
Unable to retrieve message
Could not get message

Closing evolution and reloading it will occasionally let you view the message
contents, but in cases where the subject is not brought over the first time,
there is no apparent means of forcing a full re-sync of the entire message.

Further information - when evolution is initially configured and is performing
the initial retrieval of messages from exchange, it always fails out after
obtaining some percentage of the messages in the associated Inbox/folders. 
Subsequent refreshes allow it to eventually complete, but I have yet to see a
single initial load complete successfully.

Version-Release number of selected component (if applicable):
Initially saw this behaviour on the stock fedora evolution 2.28.2-1 and
evolution-mapi 0.28.2-1.  I've since built 2.29.5 evolution and 0.29.5 of
evolution-mapi and still see the same problems.

How reproducible:
This is all very inconsistent.  If evolution runs long enough, I will
eventually have messages come across with no subject.  I will also eventually
receive messages that display no body.  If I verify these messages in the
outlook web client, they always have subjects / bodies.

Steps to Reproduce:
1. Start evolution
2. Leave evolution running
3. 

Actual results:
Messages eventually get downloaded incompletely and never fully sync.

Expected results:
Messages come across with full headers/contents intact.

Additional info:  It is worth noting that the contents of the mail account in
question are somewhat large (>6000 messages).  Either way, if there were some
way to force evolution to re-retrieve a specific message (or a group of
messages), or do a periodic resync of the contents of what shows in evolution
with what's on the server, the problem would seem to vanish. 

---

Further - The system in question is running 64bit fedora 12, and it is
connecting to an exchange 2007 server via MAPI.

Calendar items do not seem to fully/properly sync either.  Some things show,
some do not.

Contact lists in Exchange come over to evolution as an individual contact. 
Contact lists in evolution do not seem to translate back to exchange.

(yes, my apologies, probably 3 different bugs being described here.  I'll
gladly split them out however you see fit)