Email size limits depend on the service and the sending application. The table distinguishes attachment totals from whole-message limits, and keeps Outlook.com separate from Outlook client guidance.
| Service or client | Published limit | Scope |
|---|---|---|
| Gmail (personal) | 25 MB | Total attachments |
| Outlook.com | 25 MB | Whole message, including text and attachments |
| Outlook client guidance | 20 MB | Internet email accounts; client-specific guidance |
| iCloud Mail | 20 MB | Incoming or outgoing message |
| Yahoo Mail | 25 MB | Whole email in the new-mail help article |
The service and the client can differ
Microsoft's Outlook.com support page states a whole-message limit, while its broader Outlook attachment guidance describes a different limit for internet email accounts. Treat these as separate documented contexts, not as an error to average away. Organization administrators and the recipient's service can impose additional restrictions.
A worked planning example
Suppose your own draft has a 12 MB PDF and a 9 MB image. Their combined attachment size is 21 MB, calculated as 12 + 9. That is below personal Gmail's published attachment allowance, but it does not establish that every mail client or recipient will accept the message. Text, encoding, embedded images, and receiving rules can still matter.
If the file is too large, try removing unneeded pages, compressing suitable images, or using an approved storage link. A storage link has a different access model: the recipient needs permission to retrieve the file, and the link may expire or be forwarded. Confirm the intended access before sending.
Mail Drop is a different delivery path
Apple documents up to 5 GB through Mail Drop and a 30-day download window. This is a hosted attachment workflow, not an increase to every recipient's ordinary mailbox limit. Keep a durable copy elsewhere if the document must remain accessible beyond that window.
Prepare the PDF deliberately
Use local compression only when supported images are the source of the size. A text-only document may gain little. Use page extraction when the recipient needs only a section. Never remove context, signatures, or required evidence solely to satisfy a size field. Open the final file before attaching it.