"the post office moved to the shopping mall a bit further north in the street"
The place has gone or never existed. A user of Organic Maps application has reported that the POI was visible on the map (see snapshot date below), but was not found on the ground.
OSM snapshot date: 2024-05-28T17:19:44Z
POI name: Poststelle 8048 Zürich 48 Altstetten
POI types: wheelchair-yes amenity-post_office
 #organicmaps android 2026.01.26-11-Google