Email attachment size limits, app by app

What counts toward the limit

Two apps can both say 25 MB and still mean different things. Four details decide whether your file fits.

• Attachments only, or the whole email. Gmail counts the attachments you send. Outlook.com counts the whole message, text included. Yahoo Mail adds up every attachment in one email.
• The file, or the encoded file. Email turns attachments into text before sending, which RFC 2045 says makes them about 33 percent bigger. Google Workspace measures its receiving limits after encoding. Outlook on the web for work caps a message at 25% less than the configured setting to leave room for it.
• Sending, or receiving. Proton Mail lets you send 25 MB of attachments but accepts 50 MB coming in. iCloud Mail applies 20 MB both ways.
• Each file, or the whole message. Chat apps mostly limit each file. Slack's 1 GB and Telegram's 2 GB are per file, so you can send several in a row.

Who sets the number matters too. Personal accounts get the provider's limit. Work and school accounts get whatever the administrator chose: Microsoft 365 defaults to 35 MB for sending, and admins can change it.

Which email provider allows the largest attachments

Among plain email attachments, the spread is narrow:

1. Microsoft 365 work mailboxes: 35 MB by default, more if the admin raises it.
2. Gmail, Yahoo Mail and Outlook.com: 25 MB. Proton Mail sends up to 25 MB too.
3. iCloud Mail: 20 MB. Classic Outlook on POP or IMAP: 20 MB by default.

Anything bigger isn't really an attachment. Apple's Mail Drop reaches 5 GB by storing the file in iCloud and sending a link, which recipients have 30 days to use. Gmail's answer past its limit is a Google Drive link. So the real way past every email limit is the same: a link.

Chat apps go further. Telegram takes 2 GB a file, and WhatsApp 2 GB a document. Slack takes 1 GB, and a Microsoft Teams channel 250 GB a file. Discord is the outlier at 20 MB without Nitro.

Limits that come with a catch

A few rows in the table need more than one number to be true.

• Discord changed its free limit. It went up from 10 MB to 20 MB, so older guides understate it. The Discord limit page covers the Nitro tiers too.
• WhatsApp video depends on your connection. The default is 100 MB on a faster one and 64 MB on a slower one. A file sent as a document can reach 2 GB.
• Teams treats chats and channels differently. Microsoft lists 100 MB for files in chats. Files in a team's channels live in SharePoint and go up to 250 GB.
• Text messages have no single number. Apple says your carrier may set size limits for MMS, and photos and videos may be compressed to fit.
• iMessage publishes no limit. Apple says it sends high resolution photos and videos between Apple devices, but gives no maximum size, so this page doesn't guess one.

What each app does when you go over

The limit is only half the story. What happens at the limit decides how much trouble you're in.

• Gmail doesn't refuse the file. It removes it and adds a Google Drive link, stored in your Google account.
• Classic Outlook for Windows stops you with: "The file you're attaching is bigger than the server allows. Try putting the file in a shared location and sending a link instead."
• Yahoo Mail won't send a message whose attachments total more than 25 MB.
• Mail on iPhone offers to send it with Mail Drop instead.
• A Gmail message that's too big in transit bounces back with: "Your message exceeded Google's message size limits."

Per-app guides go deeper: Gmail, Outlook and Yahoo Mail.

What SendTheStuff will do past any of these limits

Almost every number in the table caps what travels inside a message. SendTheStuff will move the file outside the message, so the only limit left will be its own.

• One size for every app. SendTheStuff will take up to 5 GB per transfer free, whether the link then goes by Gmail, Slack, WhatsApp or text.
• Many files at once. SendTheStuff will hold up to 1,000 files in a transfer, behind one link.
• The original file. SendTheStuff will not compress or convert anything, unlike texts and chat apps that shrink photos and videos sent as media.
• A link that expires. SendTheStuff's links will work for 14 days, then the files will be deleted, so nothing piles up in your storage.

Until SendTheStuff launches

Here's how to get past any limit in the table with what you already have:

1. Check the table for the app you're sending from. If the file fits, attach it as usual.
2. If it doesn't, upload it to cloud storage you already use, such as Google Drive, iCloud Drive or OneDrive.
3. Set the file's sharing so anyone with the link can open it.
4. Copy the link and paste it into the email or chat. A link is a line of text, so no limit above applies to it.
5. Once the person has the file, delete it from your storage.