Sending photos that the recipient can actually open
If someone tells you your photos will not open, the fix is on your end and takes about thirty seconds. Which fix depends on which mail app you are using.
Why the recipient sees a broken attachment
Mail clients render attachment previews themselves rather than asking the operating system. So even on a machine with the HEVC codec installed, Outlook or a webmail interface may show a grey placeholder because its own image pipeline handles JPG, PNG and GIF and nothing else. The file arrives intact; the client simply cannot draw it.
Recipients rarely describe it that way. What you hear is 'your photos did not come through', which sends people looking for a sending problem that does not exist.
- Apple Mail on iPhone: use the Actual Size prompt
Attach photos and, before sending, tap the size option that appears at the top of the message (Small, Medium, Large, Actual Size). Anything other than Actual Size converts to JPG and resizes. Actual Size sends the original HEIC, which is exactly what breaks for the recipient.
- Gmail on iPhone: convert before attaching
The Gmail app attaches the file as it finds it, with no conversion. Convert first using the Files app or a Shortcut, then attach the JPG copies.
- Outlook: check the resize prompt
Outlook offers to resize large images when attaching. Accepting produces a JPG copy; declining sends the original HEIC. If your recipient reports broken attachments, this prompt is usually where it went wrong.
- Anything else: convert first
Run the files through the converter and attach the results. At quality 85 with a 2000 px cap you will fit roughly twenty photos under a 10 MB limit.
Attachment size limits worth knowing
| Service | Attachment limit | Photos at 2000 px, quality 85 |
|---|---|---|
| Gmail | 25 MB | ~50 |
| Outlook.com | 20 MB | ~40 |
| Corporate Exchange | often 10 MB | ~20 |
| iCloud Mail | 20 MB | ~40 |
| Mail Drop (Apple) | 5 GB | a lot — sent as a link |
Both ends matter. Sending 22 MB from Gmail to a corporate address with a 10 MB ceiling bounces, and the error message often blames the wrong side.
Sending a document rather than a photo? If the attachment is a photographed form, receipt or signed page, the recipient almost always wants a PDF rather than an image. Converting HEIC to PDF first makes it open in one click on any device and keeps multi-page documents together.
For more than about thirty photos, do not use email at all. A shared link through iCloud, Google Drive, Dropbox or WeTransfer avoids size limits and lets the recipient download what they want. It also avoids the format question entirely if you upload JPGs, but do check the download behaviour, since some services hand back the original format.
Checking before you send
Attach the photos, then look at the attachment name in the compose window. If it ends in
.heic, the recipient will probably have a problem. If it ends in .jpg, you
are fine. That two-second check catches nearly every case.
Common questions
- Why can't the person I emailed open my photos?
- Their mail client almost certainly cannot render HEIC. Mail apps decode attachment previews themselves rather than using the operating system, so even a machine with the right codec installed may show a placeholder.
- Does Apple Mail convert HEIC to JPG automatically?
- It does when you choose a size option other than Actual Size before sending. Actual Size sends the original HEIC untouched, which is the usual cause of failed attachments.
- How many photos fit in a 25 MB email?
- Around fifty, if they are resized to 2000 pixels at quality 85. At full resolution and quality, closer to seven or eight.
- What is the best way to send a large number of photos?
- A shared link rather than attachments — iCloud Shared Albums, Google Drive, Dropbox or WeTransfer. Email attachment limits are low and vary at both ends of the transfer.