The file to edit is pm_view.asp.
At line 163 find the following:
If pmtotal = strPMLimit or pmtotal > strPMLimit then
Response.Write ("<center><b><font face=""" & strDefaultFontFace & """ color=""" & StrHiLiteFontColor & """ size=""" & strFooterFontSize & """>You have reached your private message limit of " & strPMLimit & ".<br>To send further private messages you must clean your Inbox.</font></center>")
else
Response.Write ("<center><b><font face=""" & strDefaultFontFace & """ color=""" & strDefaultFontColor & """ size=""" & strFooterFontSize & """>You currently have " & pmtotal & " saved private messages.<br>Your Inbox limit is " & strPMLimit & ".<br>Please delete your messages once you have read them.</font></center>")
end if
Replace that with the following:
if mLev < 3 then
If pmtotal = strPMLimit or pmtotal > strPMLimit then
Response.Write ("<center><b><font face=""" & strDefaultFontFace & """ color=""" & StrHiLiteFontColor & """ size=""" & strFooterFontSize & """>You have reached your private message limit of " & strPMLimit & ".<br>To send further private messages you must clean your Inbox.</font></center>")
else
Response.Write ("<center><b><font face=""" & strDefaultFontFace & """ color=""" & strDefaultFontColor & """ size=""" & strFooterFontSize & """>You currently have " & pmtotal & " saved private messages.<br>Your Inbox limit is " & strPMLimit & ".<br>Please delete your messages once you have read them.</font></center>")
end if
end if