Email is one of the least forgiving places to send large images. A few phone photos can push a message over the attachment limit, especially when each file is 3 to 8 MB. The message may bounce, upload slowly or force the recipient to download a huge file on mobile data.
The goal is not to destroy quality. The goal is to send images at a size that matches how they will be viewed. A photo meant for a quick review, support ticket or document proof does not need to preserve every camera pixel.
Resize before compressing
Start by resizing the long edge. For ordinary email sharing, 1600 to 2000 pixels on the longest side is usually enough. For simple previews, 1200 pixels may be enough. This single step can shrink a phone photo dramatically before compression even starts.
After resizing, export as JPG for photos. Use PNG only for screenshots or graphics with sharp text. A screenshot saved as JPG may become fuzzy, while a camera photo saved as PNG may become unnecessarily large.
Keep the original separately
Do not overwrite the original photo if it matters. Create an email copy, attach that copy, and keep the original for printing, archiving or future edits. This is especially important for client work and family photos.
If you need to send many photos, compress them first and then put them into a ZIP. The recipient gets one download, and you avoid a long email full of individual attachments.