Crowd-sourced collection of geo & geo-adjacent newsletters. Started with this tweet. I've linked directly to the sign up page where applicable. Often the sign up is just on the homepage of the website. Many also indicate RSS feeds if that is your preference.
Feel free to submit new resources or propose a change in category. Some obviously span multiple categories and I just picked one.
Spatial Source https://www.spatialsource.com.au/category/emailnewsletter
Go Geomatics Canadian Spatial Times Newsletter https://gogeomatics.ca/subscribe/
Geoawesomeness https://www.geoawesomeness.com/
GIS Resources https://www.gisresources.com/subscribe-our-weekly-newsletter/
GIS Lounge https://www.gislounge.com/subscribe/
Spatial Awareness by Robin Hawkes: https://www.getrevue.co/profile/maps
xyHt https://d3data.net/xyh/landing.html
GIS Cafe https://www.giscafe.com/
ArcWatch https://www.esri.com/about/newsroom/arcwatch/
ArcNews Magazine https://www.esri.com/about/newsroom/arcnews/
ArcUser https://www.esri.com/about/newsroom/arcuser
MapLab (Bloomberg CityLab) https://www.bloomberg.com/citylab/maplab
A Closer Look (Joe Morrison) https://joemorrison.substack.com/
International Cartographic Association (ICA) https://icaci.org/email-newsletter/
OpenStreetMapUS Sign up
All that Geo https://www.allthatgeo.com/
Azavea https://www.azavea.com/newsletter/
Nosolosig http://www.nosolosig.com/sumate-a-nosolosig
GIS Ed Weekly http://blog.abs-cg.com/
Geographical Magazine http://geographical.co.uk/magazine/newsletters
Spatial Reserves https://spatialreserves.wordpress.com/
Visualising Data https://www.visualisingdata.com/ (RSS only)
Data Visualization Society https://www.datavisualizationsociety.com/ Medium: https://medium.com/nightingale
The Map Room: https://www.maproomblog.com/ (RSS only)
Datawrapper: https://blog.datawrapper.de/newsletter/
satellite-image-deep-learning https://www.satellite-image-deep-learning.com/
sUAS News https://www.suasnews.com/
UAS Magazine http://www.uasmagazine.com/newsletter/uasweek/
The American surveyor Magazine https://amerisurv.com/plans/subscribe-to-american-surveyor/
Point of Beginning Sign up
Planet Snapshots https://learn.planet.com/Snapshots_newsletter_Subscription.html
Gartner https://www.gartner.com/en/information-technology/it-newsletter-signup
CIO Dive https://www.ciodive.com/signup/
McKinsey & Company https://www.mckinsey.com/user-registration/register?source=print
Enterprisers Project https://enterprisersproject.com/
MIT Technology Review https://forms.technologyreview.com/newsletters/`
GISSuccess http://munigovguy.com/ sign up at bottom of the page
Geospatial Jobs by Ali Ahmadalipour: https://geospatial.substack.com/p/welcome-to-geospatial-jobs-newsletter