I'm using Microsoft LoadGen to simulate sending multiple mails containing attachment through Exchange server. Setup is working perfectly. I've a requirement to send some x% of a particular attachment type (say word), y % of other attachment type (say presentation) and z % of some other attachment type ( say spreadsheets). To achieve the requirement I've modified Attachment parameter under configuration file. But am NOT able to specify the percentages to use the attachment. We've a parameter as 'Weight' but am not able to understand the behavior. Please provide some help to work with 'weight' parameter I've pasted few lines from XML configuration file -------------------------------------------------------------- < AttachmentParameters > < AttachFrequency > 100 </ AttachFrequency > - < AttachmentCount > < MinimumCount > 1 </ MinimumCount > < MaximumCount > 4 </ MaximumCount > < AverageCount > 2 </ AverageCount > </ AttachmentCount > < PercentInfected > 0 </ PercentInfected > - < MessageFiles > - < MessageFile > < Weight > 10 </ Weight > < Pathname > messages\DD.pdf </ Pathname > </ MessageFile > - < MessageFile > < Weight > 10 </ Weight > < Pathname > messages\emb.docx </ Pathname > </ MessageFile > - < MessageFile > < Weight > 10 </ Weight > < Pathname > messages\emb.xlsx </ Pathname > </ MessageFile > - < MessageFile > < Weight > 10 </ Weight > < Pathname > messages\samp.docx </ Pathname > </ MessageFile > - < MessageFile > < Weight > 10 </ Weight > < Pathname > messages\this is normal text.doc </ Pathname > </ MessageFile > </ MessageFiles > </ AttachmentParameters > ---------------------------------------------------------------------------