I am using mipmmail class. When I try it from development computer it work fine, but when I test my exe at client computer, it prompt me

VFP ERROR : 107
SENDMAIL:140

How to fix it?

TIA

Here is my code

THISFORM.cusmapi1.sendmail('','',mRecipients,mSubject,mBody,mPthFile)
mNo = THISFORM.cusmAPI1.getErrorCount()
IF mNo = 0
ELSE
MESSAGEBOX(THISFORM.cusMapi1.GetErrorInfo(mNo),16,'Error')
ENDIF