Somewhere around 20 to 25MB, email gives up: your server might accept the attachment and the recipient’s still bounces it. Even when a big attachment does get through, it bloats both mailboxes and is out of date the moment the file changes. The fix isn’t a bigger attachment – it’s a link.
Share a link instead
- Put the file in OneDrive (or it may already live in SharePoint)
- Right-click it – in File Explorer or on the web – and choose Share
- Type the recipient’s email address, add a note, and send. They get a link; you’ve sent a few kilobytes.
The link always opens the current version – fix a typo after sending and they see the fixed one, with no “v2_FINAL” attachment chain.
Get the link settings right
- Specific people is the safe default: only the person you name can open it, even if the email gets forwarded on.
- Anyone with the link is fine for genuinely non-sensitive files – set an expiry date so it doesn’t live forever, and consider Block download if view-only is enough.
- Sent the wrong thing, or the deal fell through? Right-click the file, choose Manage access, and remove the link. It dies instantly wherever it was forwarded – try doing that with an attachment.
Straight from Outlook
Attach a big file the normal way and Outlook offers to upload it to OneDrive and send a link instead – take the offer. The attach menu also lists your recent OneDrive files, so you can attach as a link from the start.
A word on WeTransfer and friends
Consumer file-senders are convenient, but business files sent through them leave your controlled environment: no access review, no revoking, no record of who took a copy. Your OneDrive does the same job with the protections on. And if clients regularly need to send you oversized files, we can set up a file-request link or a proper client portal – raise a ticket and we’ll sort the right option.