We have a general mail interface programmed in Delphi that calls MAPISendMail. This works fine on all machines except one which consistently returns MAPI_E_FAILURE. This particular machine is running Windows XP and has Outlook 2003 as the default mail server. Other machines with the same setup run fine. If the default mail server is changed to Outlook Express then this machine also works fine. I have written a simple test program that just calls MAPISendMail as follows:
MapiFlags:=MAPI_DIALOG or MAPI_LOGON_UI;
This gives MAPI_E_FAILURE trying to load Outlook on the above machine but loads a blank email dialog on all other machines. I've also tried MAPILogon first and the logon works but MAPISendMail still fails with the same error. Any suggestions what might be causing this problem ?