You attach a few holiday photos, hit send, and — “the attachment exceeds the allowed limit.” The culprit is almost never the number of photos; it's that each one is a 5–12 MB camera file when it only needs to be a few hundred kilobytes to look perfect on any screen.
The real attachment limits
| Provider | Limit per email | Over the limit? |
|---|---|---|
| Gmail | 25 MB | Auto-switches to a Google Drive link |
| Outlook.com | 20 MB | Offers OneDrive link |
| Exchange / Microsoft 365 | Often 10 MB (admin-set) | Blocked; use OneDrive/SharePoint |
| Yahoo Mail | 25 MB | Blocked |
| Apple Mail (iCloud) | 20 MB | Mail Drop up to 5 GB |
Two catches most people miss. First, both sides have a limit — you can send 24 MB from Gmail, but if the recipient is on a 10 MB corporate server it bounces. Aim under the smaller number. Second, email inflates attachments by about a third because they are encoded as text (base64). A 25 MB limit is really ~18–20 MB of actual files.
The fix in three steps
- Resize to about 1600–2048px on the long edge. That is more than enough for any screen and even for a decent print at that size.
- Compress to WebP or JPEG at quality ~75.
- Batch it. Drop the whole set in at once rather than one at a time.
A typical 5 MB phone photo becomes 200–400 KB — meaning you can comfortably attach a dozen or more and still sit far below any limit. Drop your images into the compressor, pick the “Email / sharing” style preset, and download them all in one go.
When to send a link instead
If you're sending original full-resolution files (for print, a designer, or archiving), don't fight the limits — use a cloud link (Drive, OneDrive, WeTransfer). Compression is for when the recipient just needs to see the images clearly, which is the vast majority of the time. Not sure how low you can push quality safely? See compress without losing quality.
A note on privacy
Photos carry EXIF metadata — including GPS coordinates of where they were taken. Before emailing images to someone you don't want knowing your home address, strip metadata (a good compressor does this automatically). More on that in is online compression safe?
Frequently asked questions
What is the maximum email attachment size? +
It varies by provider. Gmail allows 25 MB per message (larger files switch to a Google Drive link). Outlook.com allows 20 MB, and corporate Exchange is often capped at 10 MB. Yahoo allows 25 MB and Apple Mail 20 MB (with Mail Drop for larger). Crucially, the sender AND the recipient limits both apply — aim under the smaller of the two.
How do I make photos small enough to email? +
Resize the dimensions to around 1600–2048px on the long edge and compress to WebP or JPEG at quality ~75. A typical 5 MB phone photo drops to 200–400 KB — so you can attach a dozen and stay well under any limit — with no visible loss on screen.
Why does my email say the attachment is too large when the file looks small? +
Email encodes attachments in a text format (base64) that inflates them by about 33%. So a 20 MB file actually travels as ~27 MB. Leave headroom: treat a 25 MB limit as roughly 18–20 MB of real files.
Should I zip images before emailing? +
Rarely worth it for photos. JPEG/WebP files are already compressed, so zipping them saves almost nothing and adds a step for the recipient. Compressing the images themselves is far more effective than zipping them.