User Agent: Mozilla/5.0 (Windows NT 5.1; rv:20.0) Gecko/20100101 Firefox/20.0 Build ID: 20130409194949 Steps to reproduce: Executed call to MapiSendMail function in mozMapi32.dll with MAPI_DIALOG flag set and tested result Thunderbird 17.0.5 on XP SP3 Actual results: 'Write' window displayed correctly but not as a modal dialog; MapiSendMail function returns a result of 0 (SUCCESS_SUCCESS) as soon as 'Write' window is displayed and execution of calling routine continues while 'Write' window is displayed. Expected results: 'Write' window should have opened as a modal dialog; execution of calling routine should wait for closing of modal dialog. MapiSendMail function with MAPI_DIALOG flag should not return a result until user closes 'Write' window by either sending mail (Result=SUCCESS_SUCCESS) or closing without sending (Result=MAPI_E_USER_ABORT). Correct behaviour is exhibited by all other MAPI clients tested (Outlook, Outlook Express)