A van from episode 2 season 5.
After a quick research on the internet, I'm almost sure it's a 1955 Ford F-100 "Panel Van"

Here's the photo :


Voilà !

[EDIT] : This truck is used a few seconds by a delivery boy who brings to Quinn some flowers.

Link to Daria page : http://www.imcdb.org/movie_118298-Daria.html