#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "(?x)^\/([ac])\/(\d{1,4})\/(\d{1,4})\/([a-zA-Z\d\._-]+)\/(.*)"
Local $sString = "/a/94/403/webolizer/1461075495.84270.webmail5581.mynet.com%3A1228350129winmail.dat"
Local $sSubst = ""
Local $sResult = StringRegExpReplace($sString, $sRegex, $sSubst)
MsgBox($MB_SYSTEMMODAL, "Result", $sResult)
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for AutoIt, please visit: https://www.autoitscript.com/autoit3/docs/functions/StringRegExp.htm