How to Compress Images for Email Attachments

Sending a photo from your phone as an email attachment and having it bounce back — or never arrive — is a frustrating but common problem. Email servers impose strict size limits. Modern smartphone photos are often 4–8 MB each, and many servers reject anything over 10 MB total. This guide explains how to compress images for email so they always arrive.

Email Attachment Size Limits by Provider

Email Provider	Send Limit	Receive Limit
Gmail	25 MB	50 MB
Outlook / Hotmail	20 MB	25 MB
Yahoo Mail	25 MB	25 MB
Apple Mail (iCloud)	20 MB	20 MB
Corporate email (typical)	10–15 MB	10–25 MB

These are the total attachment size limits, not per-file. Sending three 5 MB photos to a Gmail user from an Outlook account can fail even though each limit seems sufficient, because email encoding adds approximately 33% overhead to file sizes.

What File Size to Target for Email Images?

A practical target is under 500 KB per image for email attachments. This ensures:

✓You can attach multiple images without hitting server limits.
✓Emails send and download quickly on mobile networks.
✓The image still looks good when opened at full size.
✓Recipients on older devices or slow connections can open the email without problems.

For a single important image (a professional photo, a product shot), 200–500 KB gives excellent quality at a reasonable size. For multiple attachments, aim for 100–200 KB each.