Email Attachment Size Limits by Provider
Quick answer
Most email providers cap attachments at 20–25 MB. Gmail and Yahoo allow up to 25 MB; Outlook.com and iCloud Mail around 20 MB.
| Provider | Send limit | Larger files via |
|---|---|---|
| Gmail | 25 MB | Google Drive link |
| Outlook.com | ≈ 20 MB | OneDrive |
| iCloud Mail | 20 MB | Mail Drop (up to 5 GB) |
| Yahoo Mail | 25 MB | Cloud link |
| Proton Mail | 25 MB (total message) | — |
Receiving limits can differ from sending limits, and a company mail server may impose a smaller cap. When in doubt, keep attachments under 10 MB to be safe across providers.
Troubleshooting
- “Attachment size exceeds the allowable limit.”
- Your file is over the provider cap. Compress it, or send a cloud link instead.
- The email sends but never arrives.
- The recipient's server may have a smaller limit. Try under 10 MB or share a link.
Sources
- Send attachments with your Gmail message — Google · verified 2026-06-19
- Insert or attach files in Outlook.com — Microsoft · verified 2026-06-19
- Use Mail Drop to send large attachments — Apple · verified 2026-06-19
- Attach and download files in Yahoo Mail — Yahoo · verified 2026-06-19
- Proton Mail size and rate limits — Proton · verified 2026-06-19
Last verified · reviewed occasionally.
Change history
- — Initial publication with provider sources.