"Either there is no default mail client or the current mail client cannot fulfill the messaging request" error message when you send e-mail from third-party program in Outlook
1.
http://support.microsoft.com/kb/813745 Try this.
2. “This worked for me: Program files-> common files -> system ->msmapi ->1033 ->delete msmapi32.dll. When you restart outlook the file recreates itself and everything works.
Article ID: 31, Created On: 5/6/2011, Modified: 5/6/2011