If you notice image sizing issues when sending PoliteMail HTML messages, but they don’t appear on your machine, you may want to check Windows text scaling.
Text scaling is a feature on newer Windows laptops with high-resolution displays, to auto-scale the screen content to make it more readable. The problem is that this scaling creates issues with HTML rendering on other systems without text scaling.
The default text-scaling on modern laptops seems to be 150%. But when creating images, and when working with HTML email pages and PoliteMail templates, you will want Windows text-scaling set to 100%.
Access Windows text scaling using Windows > Control Panels > Display