What is the attachment limit in Gmail, Outlook, Yahoo and iCloud?
Limits per email, checked against each provider's help pages in October 2026
| Service | Limit per email | Over the limit |
|---|---|---|
| Gmail (personal) | 25 MB | Gmail turns the attachment into a Google Drive link |
| Gmail (work or school) | Set by your Google Workspace admin | Drive link |
| Outlook.com | 25 MB of attached files | Share from OneDrive (up to 2 GB per file) |
| Microsoft 365 work or school | 35 MB to send by default; admins can set up to 150 MB | OneDrive or SharePoint link |
| Yahoo Mail | 25 MB, sent and received | Cloud storage link |
| iCloud Mail | 20 MB | Mail Drop, up to 5 GB |
The recipient's server has its own limit too: a 24 MB email that leaves Gmail can still bounce at a company mail server set to a smaller maximum. The classic Outlook desktop app also applies its own 20 MB default to POP and IMAP accounts, whatever the provider allows.
Why does a 20 MB attachment fail under a 25 MB limit?
Email carries files as text using base64 encoding, which writes every 3 bytes as 4 characters: the attachment grows by about 33% on the way. Microsoft documents the same 33% increase for messages that leave its servers. Some services count the encoded size, others the raw size, so keep your attachments at about three-quarters of the stated limit, around 18 MB for a 25 MB limit and 15 MB for iCloud.
What size should photos be for email?
Typical JPEG sizes for a 4:3 photo
| Use | Long edge | JPEG quality | Typical size each |
|---|---|---|---|
| Viewing on phones and laptops | 1,600 px | 70–80 | 150–300 KB |
| Viewing on large screens | 2,048 px | 75–80 | 300–550 KB |
| Printing up to 6 × 4 in (15 × 10 cm) | 1,800 px | 85 | 400–800 KB |
| Archiving or large prints | Full size | Original | 2–5 MB: send a link instead |
How many photos fit in one email?
| Size of each photo | About 18 MB of attachments (25 MB limit) | About 15 MB (iCloud's 20 MB limit) |
|---|---|---|
| 3 MB (phone original) | 6 | 5 |
| 1 MB | 18 | 15 |
| 500 KB | 36 | 30 |
| 300 KB | 60 | 50 |
| 200 KB | 90 | 75 |
How do I shrink photos for email in a few seconds?
- Open the compressor in any browser, on a computer or a phone.
- Drop your photos. Up to 100 at a time are processed; the first file downloads free, and Pro unlocks every file plus a ZIP download.
- Choose JPG as the output so every recipient can open them. HEIC photos from an iPhone open in Safari and come out as JPG.
- Turn on Limit width and type 2048 (or 1600 for phone viewing), then set Quality to 75.
- Compress, download and attach. For a fixed size per photo instead, use Image to 500 KB.
Does zipping photos make them smaller?
Barely. JPEG photos are already compressed, so a ZIP archive of them is usually only a percent or two smaller than the photos themselves. A ZIP is handy for sending one file instead of forty, but only resizing and recompressing the photos actually brings the total down.
When should I send a link instead of attachments?
When the recipient needs the full-resolution originals, for printing large or editing, or when the set is too big even after resizing. Google Drive, OneDrive and iCloud Mail Drop all send a link, so inbox limits do not apply. For photos placed inside a newsletter rather than attached, see images for email newsletters.