Clinic guide · 2026
Email photo attachment too large
Email rejects oversized photos when the message or attachment exceeds the provider’s size limit (often around 20–25 MB total). Compress or resize images — or use a link — before sending.
What “attachment too large” means
Email systems limit:
- Per-attachment size
- Total message size (body + all attachments)
- Sometimes mailbox quotas on the receiving side
Consumer defaults people hit in practice:
| Provider (typical) | Rough ceiling people notice |
|---|---|
| Gmail | About 25 MB total per message |
| Outlook.com / many Microsoft 365 tenants | Often ~20–25 MB, tenant policies vary |
| Corporate mail gateways | Can be much lower |
Exact numbers change; the bounce text is authoritative.
Phone photos vs email reality
One modern phone burst can exceed an entire email budget. Symptoms:
- Client refuses to attach
- Message sits in Outbox
- Bounce: “message too large”
- Recipient gets a stripped message or blocked external images only (different issue)
Fix options (in order)
- Resize + compress photos to JPG under a few hundred KB to a few MB each, depending on how many you send.
- Send fewer images per message.
- Use a file link / shared drive when the recipient allows it.
- Avoid mailing HEIC to unknown recipients.
Forms vs email
If you are attaching a photo for a portal that also accepts email uploads, follow the portal’s KB limit, which is usually far stricter than Gmail’s 25 MB. See the under-100 KB / 200 KB guide for that case.
This site does not send email or host your files. For a local compressor before you attach, use the Fernpix link below.
FAQ
Why did the email send on my phone but bounce for the recipient?
Your outbound path may accept the message while the recipient server enforces a lower limit, or corporate gateways strip large attachments.
Is HEIC a problem in email too?
Yes. Some recipients cannot open HEIC. Prefer JPG when sending to mixed devices.
Should I zip the photos?
A zip can help organization but does not magically beat a hard total-size cap. Compress images first.