with a `.mailmap` file,
see https://git-scm.com/docs/gitmailmap.

Unfortunately, gitlab does not honor yet this file
(https://gitlab.com/gitlab-org/gitlab/-/issues/14909),
but with `git shortlog -sne` on the `trailer `branch we get:

```txt
  4349  Markus QUARITSCH <markus.quaritsch@tugraz.at>
  1300  Michael KRISPER <michael.krisper@tugraz.at>
   401  Harald MARTINI <harald.martini@ivt.tugraz.at>
   182  Terry Burns <Terry.Burns@ricardo.com>
   175  Raphael LUZ <luz@ivt.tugraz.at>
   160  Vasilis Kouliaridis <vasilis.k@emisia.com>
   104  Franz KOBER josef <franz.josef.kober@ivt.tugraz.at>
    50  Kostis Anagnostopoulos <ankostis@gmail.com>
    33  Glenn Zarb <glenn@ascentsoftware.eu>
    16  Stefan BRANDT <brandt@ivt.tugraz.at>
    12  Dana Nurse <Dana.Nurse@ricardo-aea.com>
     9  Stefan MEYER <stefan.meyer@student.tugraz.at>
     2  Kumara Raghavendra <kumargel@yahoo.com>
     2  Raphael Kalchgruber <kalchgruber@ivt.tugraz.at>
```