I am helping someone else with the server edition and they too have this "Invalid wire-type; this usually means you have over-written a file without truncating or setting the length; see http://stackoverflow.com/q/2152978/23354"
This occurs when they are attempting to send email for any entity. The host is an ubuntu server 64Bit. I have never seen this issue before.
I have upgraded the Ubuntu host and Manager to the latest version and the issue persists.
Testing the mail under settings mail settings works fine. The test message sends and is received OK.
I have also tested with a new demo company file which is blank. Generate a P & L report then email and the error above comes up.