Optimize images for email

Optimize the four product photos for our weekly newsletter so they load fast and look sharp: export each at 600px wide for desktop and a separate 320px-wide version for mobile, save as progressive JPEGs under 150 KB, and name files with SKU and size. Replace the originals in the campaign, update alt text with product names, and send to Marcus to run an inbox preview before scheduling.

Before I finalize images for the weekly newsletter, make them approval-ready: show the exported file sizes next to each image, surface a 600px and 320px version, call out any image over 150 KB, suggest a compression level to hit target size while keeping product detail, and note which three images need a recolor or crop to avoid dark bands on mobile.

I exported the newsletter images but three files are over 150 KB and previews load slowly; Marcus will balk at poor load times and Sarah will want image quality preserved. I don't know whether to reduce dimensions, increase compression, or use a different format. What's the most likely trade-off and the fastest adjustment that keeps product detail while meeting the 150 KB guideline?

We keep exceeding the 150 KB per-image guideline and inbox previews slow, causing delays and pushback from ops. I need a repeatable rule to prevent this: what export settings, format choices, and a one-line acceptance test should every designer follow so images consistently meet our email performance standard?