In short
- Email is the worst channel for video: Gmail and Outlook.com stop at 25 MB per message, Exchange business accounts at 10 MB by default.
- WhatsApp and Slack accept much bigger files, but the client has to download them, and the file stays in the chat for good.
- A link is almost always better than an attachment: the client clicks, the video plays, nothing fills their inbox.
- Most failed sends are permission problems: a drive link set to restricted, or a work account that blocks outside shares.
- For client videos that only matter for a few days, a link that expires is the cleanest option.
To send a large video file to a client, don’t attach it: upload it somewhere that gives you a link, check that the link opens without an account or a permission request, and paste it into your email, WhatsApp or Slack message. Email attachments stop at around 25 MB, which a few minutes of screen recording can easily exceed. Chat apps accept bigger files, but the client has to download them, and the file stays in the chat forever.
Below: the limits of each channel, the options compared, the permission traps behind “I can’t open it”, and why a link that expires suits most client videos.
Attachment limits by channel
These limits change from time to time, so treat them as a guide.
| Channel | Limit for one file or message | What happens above it |
|---|---|---|
| Gmail (personal) | 25 MB per message | Gmail removes the attachment and adds a Google Drive link instead |
| Gmail (Google Workspace) | Set by the administrator | Depends on the company |
| Outlook.com | 25 MB per email, text and attachments together | You can share a OneDrive link instead (linked files up to 2 GB) |
| Outlook app with an internet account | 20 MB | Microsoft suggests uploading to a cloud service and sending the link |
| Outlook with Exchange (business) | 10 MB by default | Same, or ask your administrator |
| Apple Mail with Mail Drop | Attachments up to 5 GB | Sent as a link that expires after 30 days |
| WhatsApp, sent as a video | Limited in size, and the video may be compressed | Send it as a document instead |
| WhatsApp, sent as a document | 2 GB | Use a link |
| Slack | 1 GB per file | Use a link |
From each service's own help pages, checked November 2026. WhatsApp's video limits depend on your phone and connection: see its help center.
Two things stand out. Email limits apply to the whole message, so the real space for a video is a little less than the number. And the receiving side has limits too: Apple notes that the recipient’s email app may have a smaller limit that stops a Mail Drop attachment from arriving. On WhatsApp, the size and quality of a video sent as media aren’t fixed numbers; check WhatsApp’s help center on sending media for your phone.
Why attachments are the wrong tool for client video
Even when a video fits, sending the file has costs that land on the client.
- They have to download it before they can watch. On a phone, with a 300 MB file, that’s often where it stops.
- It fills their inbox or chat. Some companies have mailbox quotas; a video in WhatsApp takes space on their phone.
- It never goes away. A file in an inbox or a chat stays there for years, including whatever was on your screen: another client’s tab, an admin panel with real customer names.
- It’s easy to forward. An attachment travels with the email thread, to people you’ve never met.
A link solves most of this. The client clicks, the video plays in the browser, and you decide how long it’s available.
Your options compared
| Option | What the client gets | Plays in the browser | How long it stays online |
|---|---|---|---|
| Email attachment | A file in their inbox | ✗ they download it | Forever, in their inbox |
| WhatsApp or Slack file | A file in the chat | ~ depends on the app and the size | Forever, in the chat |
| Cloud drive link (Google Drive, OneDrive, Dropbox) | A link to a drive page | ~ usually, if permissions are right | Until you delete it |
| Transfer service (WeTransfer) | A download page | ✗ built for downloading | Depends on the plan |
| Screen recorder share link | A video page | ✓ | Depends on the tool: forever or until it expires |
Cloud drive links
The option most agencies already have. Upload the file to Google Drive, OneDrive or Dropbox, copy the share link, paste it in the message. It works well when you get the permissions right (see below), and it’s a good home for files the client should keep, like the final edit of a promo video.
Its weak points for everyday client videos: you have to upload and set sharing every time, the video stays in your drive until you remember to delete it, and the client lands on a drive page rather than a video.
Transfer services
WeTransfer and similar services are built to move big files from one person to another, and they’re good at it. They make sense when the client needs the file itself, for example a video they’ll publish on their own channels. Free plans have caps: WeTransfer’s free plan allows 10 transfers or 3 GB in total in any rolling 30-day window, according to its help center.
For a three-minute design review, they’re more than you need. The client gets a download, not something they can watch in a click.
Screen recorder share links
If you record with a tool that uploads as you stop and gives you a link, you skip the export, upload and sharing steps. The question to ask is what happens to the video afterwards: does it live in a cloud library forever, or does the link expire?
The permission traps
When a client writes “I can’t open it”, it’s almost always one of these.
- The drive link is restricted. In Google Drive, a file with general access set to Restricted opens only for people you added by email. Set it to Anyone with the link, so it opens without signing in to a Google account, or add the client’s address.
- The client’s company blocks outside shares. Google notes that an administrator may restrict “anyone with the link” sharing for work and school accounts. If a client on a corporate account can’t open your link, this is a likely cause.
- The link asks for an account. Some services want the viewer to sign in or create one before playing. Many clients give up there.
- The file isn’t ready yet. If you send the link before the upload or processing has finished, the client sees an error or a spinner.
- The link went to a group. Not a technical failure, but the most common privacy one. Send it to the person who has to act on it.
Link previews: why they matter
When you paste a link into WhatsApp, Slack or Mail, the app tries to show a preview with a title and an image. A good preview tells the client what the video is about before they click, and makes the message look intentional instead of like spam.
Previews don’t always appear. Slack’s help center notes that a link may not expand if the page doesn’t provide preview data or points to a private page or file. A restricted drive link, in other words, usually arrives as a bare URL.
Whatever you send, write one line next to the link that says what it is and what you need:
Homepage round two, 3 minutes. Can you confirm the header by Friday?
https://justrec.app/v/k3f9Qa
We cover the rest of that message in how to get clients to actually watch your videos.
Why a link with an expiry is the cleaner option
Most client videos have a short life. A design review is replaced by the next round; a bug report is useful until the bug is fixed. Yet with attachments and drive links, every one of those videos stays somewhere for years.
A link that expires matches how client videos are actually used. The client watches it within a few days, the online copy is deleted afterwards, and old links stop working by themselves, including any copy that was forwarded. You keep the original, so you can send it again if someone asks. We explain the reasoning in why expiring video links are safer.
Not every video fits this. Training material and handovers the client will rewatch for months need a permanent home, such as a shared folder the client owns. Our guide to website handover videos covers where to keep those.
If you still need to send the file
Sometimes the client genuinely needs the MP4: to publish it, to archive it, or because their company only accepts attachments. Then:
- Make it smaller first. Lower the resolution or trim the dead time at the start and end. Our guide to making a screen recording smaller on Mac shows how.
- Use the channel’s own large-file option: Mail Drop in Apple Mail, a Drive link in Gmail, a OneDrive link in Outlook, a document in WhatsApp.
- Name the file clearly, with the client, the subject and the date, so they can find it later.
- Check what’s on screen before you send something that will live in their inbox for years. The screen recording privacy checklist takes a minute.
For more on where sending videos fits in client work as a whole, read our guide to async video for client communication, or see how we approach it on send video to clients.
Sources
- Gmail Help: Send attachments with your Gmail message, checked November 2026.
- Microsoft Support: Unable to attach files in Outlook.com, checked November 2026.
- Microsoft Support: Send large files with Outlook, checked November 2026.
- Apple Support: Mail Drop limits, checked November 2026.
- WhatsApp: Messaging, 2 GB maximum for documents, checked November 2026.
- WhatsApp Help Center: How to send media, contacts, or location, checked November 2026.
- Slack Help Center: Add files to Slack, checked November 2026.
- Slack Help Center: Share links and set preview preferences, checked November 2026.
- Google Drive Help: Share and manage access to files and folders, checked November 2026.
- WeTransfer Help Center: Plan limits, checked November 2026.
Frequently asked questions
What is the largest video I can attach to an email?
Personal Gmail and Outlook.com accounts allow 25 MB per message, attachments and text together. Business accounts depend on the administrator, and Microsoft's default for Exchange is 10 MB. A few minutes of screen recording often goes past these limits.
How do I send a video that is too big for WhatsApp?
Send it as a document instead of a video: WhatsApp allows documents up to 2 GB, while videos sent as media can be limited in size or compressed. For anything bigger, or anything the client needs to watch rather than keep, send a link.
What is the best way to send a large video to a client?
Upload it somewhere that gives you a link that plays in the browser, then paste the link into your message. Check that the client can open it without an account or a permission request, and decide how long it should stay online.
Why can't my client open my Google Drive link?
Usually because the file's access is set to Restricted, so only people you added can open it. Set general access to Anyone with the link, or add the client's address. Some company accounts also block files shared from outside the organization.
