Sorry - still no joy.

It is quite clear that there is no problem with the actual Mail Merge - I can see both emails (to myself & my wife) when I preview the results. It is just when I actually ask the system to 'Finish & Merge' and 'Send Email Messages' and then in the 'Merge to Email' box when I click OK to send all messages I simply get a flicker on the screen and then nothing - my message reverts to the master copy. No sign again of the Outlook error message.

Any more suggestions before you retire for the night?