Why is there a file size limit on email attachments?
Email providers cap attachments tightly around 20MB, which makes sending bulk PDFs or large media impossible without failing. This mismatch forces people to deal with sudden upload rejections and floods support teams with tickets asking for alternatives.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1Using cloud storage or file sharing services like OneDrive
- 2Sending documentation links on how to use file sharing services
- 3Forwarding company-wide emails from the CIO explaining proper file transfer methods
- 4Lowering the scan resolution to 200 DPI and changing the format to Compact PDF
- 5Deleting Sent Items from the mailbox
- 6Increasing the message size limit in Exchange Online
- 7Formatting the internal hard drive on the copier
In their words
Unedited, most upvoted first, each linked to the thread it came from.
“If one more person asks me why they can't send 50 PDF's in an email, I am going to lose, my god damn mind.”source ↗
“Can you bump up the file size limit for email attachments? I'm trying to send 51 PDF's in an email it just keeps failing.”source ↗
“"WHAT do you MeAn the limit is 20mb?!" I thought it was higher.”source ↗
“I had a customer emergency line call me cause they couldn't email a 200GB file.”source ↗
“The amount of executives, high level sales people and account managers that sent tickets to L1 pissed about this was pretty astounding”source ↗
Where this came up
People with this problem also raised
- 2How to automatically deliver digital files to buyers on Amazon and eBay
- 3Why do large mailbox migrations to M365 fail?
- 2Why are wedding invitations taking weeks or months to arrive in the mail?
- 2Accidentally sent confidential internal email to the wrong person
- 3How to fix sync problems on large Outlook mailboxes
- 3Why is accounting software automatically emailing my clients?