Why won't my Keynote send by email?
Because it is too big. Most email services cap a message at about 20 to 25 MB, and one video clip or a dozen full-resolution photos takes a Keynote past that. The fix is to stop attaching the file.
The direct answer
Your Keynote is larger than your email provider accepts. Gmail caps attachments at 25 MB, most other services sit between 20 and 25 MB, and the receiving server can be stricter. Attachments also grow by about a third when encoded for sending. Send the file through Mail Drop, or send the deck itself as a link.
Why Keynote files get this big
Keynote stores every image and clip inside the file at its original size. A phone video, a 4K render, photos straight off a camera: each adds megabytes even when it is shown small on the slide. Trimmed clips keep their full length until you run Reduce File Size.
What Apple Mail offers
When an attachment is too large for your mail server, Apple Mail offers Mail Drop. The file uploads to iCloud and the recipient gets a download link: up to 5 GB, available for 30 days. They still receive a .key, so they need Keynote on a Mac, iPhone or iPad to open it.
What to do instead
Pick by what the recipient will do with the deck.
- Edit it: Mail Drop, or a WeTransfer or Dropbox link.
- File or print it: export a PDF (File → Export To → PDF). It loses builds and video, and can still be large.
- Watch it: export to HTML, compress the folder, upload it to Linkdeck and paste the link into the email. It plays on any phone or laptop without Keynote.
Questions
Will Reduce File Size get it under 25 MB?
Rarely, if there is video. It scales images down and can convert movies to a smaller format, which might take 300 MB to 100 MB: still four times too big.
Can I zip the Keynote to make it small enough?
Usually not. The images and video inside a Keynote are already compressed, so zipping barely changes the size.
Does the person I email the link to need Keynote?
No. A Linkdeck link opens in any modern browser on iPhone, Android, Windows or Mac, with no app and no Apple ID.
Put a link in the email instead
Export to HTML, compress, upload. One deck up to 200 MB is free for 3 days; Pro (€12 a month) takes 500 MB and keeps the link.