Email attachment size limits: Gmail, Outlook, Yahoo and iCloud
Every email service caps how big an email can be. Go over it and your message bounces or won't send. Here are the current limits from each provider's own help pages, why a 20 MB file can still be "too big," and how to send larger files.
Gmail: 25 MB to send, up to 50 MB to receive; bigger files go as a Google Drive link. Outlook.com / Outlook on the web: 34 MB for files from your computer, 2 GB via OneDrive. Microsoft 365 work accounts: 35 MB to send and 36 MB to receive by default (admins can raise it to 150 MB). Yahoo Mail: 25 MB total. iCloud Mail: 20 MB, or up to 5 GB with Mail Drop. Limits apply to the whole email after encoding, which adds about a third.
See also: How to attach in each app: sending photos and attachments by email.
Attachment limits by provider
| Provider | Send | Receive | For bigger files |
|---|---|---|---|
| Gmail (personal) | 25 MB | Up to 50 MB | Gmail puts files over the limit in Google Drive and adds a link |
| Outlook.com / Outlook on the web | 34 MB per local file | Not stated | OneDrive files up to 2 GB |
| Classic Outlook app with Outlook.com or Gmail | 20 MB per email | Depends on provider | Share a cloud link |
| Microsoft 365 (work/school) | 35 MB default | 36 MB default | Admins can set 1–150 MB; OneDrive up to 2 GB |
| Yahoo Mail | 25 MB total attachments per message, sending or receiving | Share a cloud link | |
| iCloud Mail | 20 MB per message | Up to 5 GB with Mail Drop | |
Checked on each provider's help pages on October 30, 2026. Gmail's 50 MB receive limit comes from Google's 2017 Workspace Updates announcement; the current Gmail help page states only the 25 MB sending limit. We left AOL out because we couldn't confirm its limit on an official AOL page.
Why a 20 MB file can be "too big" for a 25 MB limit
Email was designed for text. To send a file, your email app converts it into text characters (called Base64 encoding), and that makes it bigger. Microsoft's Exchange Online limits page says messages sent outside its data centers are subject to "an additional 33% translation encoding increase."
So the rough rule is: the file can be about three-quarters of the limit. A 20 MB file becomes roughly 27 MB once encoded, which is over Gmail's 25 MB. Microsoft says Outlook on the web allows for this by limiting what you can send to 25% less than the configured maximum.
Want to check before you hit send?
The receiver's limit matters too
Your email has to fit both your limit and theirs. If you send a 30 MB email from a Microsoft 365 account to a Yahoo address, Yahoo's 25 MB cap applies and it bounces. When you don't know what the other person uses, keep attachments small or use a link.
A bounce for size usually mentions "message size exceeds" or an SMTP code such as 552.
How to send larger files
1. Share a cloud link (best for big files).
- Gmail: click the Google Drive icon when writing, or just attach the file; Google says files over 25 MB are automatically added as a Drive link.
- Outlook: attach from OneDrive; Microsoft says OneDrive attachments can be up to 2 GB.
- iPhone, iPad and Mac Mail: turn on Mail Drop, which Apple says allows up to 5 GB.
- Any provider: Microsoft's help also suggests uploading to a service like OneDrive, Dropbox, iCloud or Google Drive and pasting the link.
Check the sharing setting. "Anyone with the link" is easiest; "Only people I choose" is safer for private files.
2. Compress the file. Zip a folder of documents (right-click › Compress on Mac, or Send to › Compressed (zipped) folder on Windows). Zipping helps a lot with documents, less with photos and videos, which are already compressed.
3. Shrink images. Phone photos are often 3–8 MB each.
4. Split it up. Send several smaller emails, numbered "1 of 3," "2 of 3."
Rules of thumb: under 10 MB, attach it. Between 10 and 20 MB, attach it only if you know the other person's provider accepts it. Over 20 MB, or a file you'll update later, send a link. Links also keep the other person's inbox small, and you can stop sharing later.
Big attachments and spam filters
Size alone rarely sends mail to spam, but some file types do. Many providers block .exe and similar files outright, and unexpected attachments from unknown senders get extra scrutiny. If you send attachments to customers or a list, link to the file instead. Our guide on attachments and spam explains the details.
Questions people ask
- What is Gmail's max attachment size?
- 25 MB to send. Gmail can receive messages up to 50 MB. For bigger files, Gmail adds a Google Drive link instead.
- What is the attachment limit in Outlook?
- Outlook on the web allows 34 MB for files from your computer and 2 GB via OneDrive. The classic Outlook app limits Outlook.com and Gmail accounts to 20 MB per email. Microsoft 365 work accounts default to 35 MB to send.
- What is the Yahoo Mail attachment limit?
- Yahoo says attachments in one message must not exceed 25 MB in total, sending or receiving.
- How do I send a file bigger than 25 MB by email?
- Share it as a Google Drive, OneDrive, Dropbox or iCloud link, use Mail Drop on Apple devices, or compress it into a .zip file.
- Why does my 20 MB file say it's too large?
- Email encoding adds about 33% to the size, so a 20 MB file becomes about 27 MB, which is over a 25 MB limit.
- Google: Attach files to Gmail messages
- Google Workspace Updates: Receive emails of up to 50 MB in Gmail (2017)
- Microsoft: Attach files in Outlook (34 MB, OneDrive 2 GB)
- Microsoft: Reduce attachment size to send large files with Outlook
- Microsoft Learn: Exchange Online limits
- Yahoo: Message size limits in Yahoo Mail
- Apple: Mailbox size and message sending limits in iCloud