If you want to create an e-mail for each sheet with the attachments from column 5 on those sheets then you need to change the code to loop through all the sheets and then loop through the rows on each sheet for the attachments, but set the other values from the first data row which is common to all.
You also need to determine the last row from the column with the attachments and not from the first column, which only has one row after the header.
Then there is the issue of the folder. While the code is transportable between users, the folder and its contents are not shared. They would each have to have the desktop folder and the files it contains - or put the files in a folder to which all the users have access and change the path to match.
Note the earlier comments abolut the extension.
Sub sendemail()
Dim olapp As Outlook.Application
Dim olmail As Outlook.MailItem
Dim i As Long, j As Long
Dim xlSheet As Worksheet
Dim strPath As String: strPath = Environ("userprofile") & "\desktop\handbook\"
Dim fso As Object
Set fso = CreateObject("Scripting.FileSystemObject")
Set olapp = New Outlook.Application
For j = 1 To ActiveWorkbook.Worksheets.Count
Set xlSheet = ActiveWorkbook.Sheets(j)
Set olmail = olapp.CreateItem(olMailItem)
For i = 2 To xlSheet.Cells(xlSheet.Rows.Count, 5).End(xlUp).Row
With olmail
.To = xlSheet.Cells(2, 1).Value
.CC = xlSheet.Cells(2, 2).Value
.Subject = xlSheet.Cells(2, 3).Value
If fso.FileExists(strPath & xlSheet.Cells(i, 5).Value & ".ext") Then
.Attachments.Add strPath & xlSheet.Cells(i, 5).Value & ".ext"
Else
Debug.Print strPath & xlSheet.Cells(i, 5).Value & ".ext - does not exist"
End If
.Display
End With
Next i
Set olmail = Nothing
Set xlSheet = Nothing
Next j
Set olapp = Nothing
End Sub