Email size limits on shared hosting

We limit email attachments to 20MB on shared hosting accounts. This prevents performance issues, protects against security threats and maintains compatibility with other email providers.

You can send larger files using dedicated file sharing services like Dropbox or WeTransfer. These platforms handle large transfers more efficiently than email systems.

Why email size limits exist

Email systems were designed for short text messages, not large file transfers. Three factors make size limits necessary across the email industry.

Performance

SMTP, the protocol that powers email, was built for text communication. Attachments were added later through extensions, but the underlying system struggles with large files. Mail servers scan every incoming message for viruses and spam, which consumes significant resources when processing large attachments. This scanning protects your account but slows down delivery when files exceed reasonable sizes.

File transfer protocols like FTP handle large files more efficiently because they were designed for that purpose from the start.

Security

Email services use a limited number of ports to receive data. Attackers can exploit this by flooding these ports with oversized messages, overwhelming the server and preventing legitimate emails from reaching their destination. Size limits reduce the impact of these denial-of-service attacks by restricting how much data can pass through at once.

Compatibility

Most email providers impose their own size limits. Gmail allows 25MB attachments, Outlook.com permits 20MB and Exchange accounts default to 10MB. When you send an email with a 25MB attachment to someone using an Exchange account with a 10MB limit, the message fails to deliver.

Our 20MB limit balances compatibility across major providers while allowing reasonably sized attachments to pass through. This becomes particularly important when migrating your emails between services, as oversized messages can cause migration failures.

Sending large files

File sharing services handle large transfers more reliably than email. These platforms generate a download link that you include in your email message instead of attaching the file directly.

Popular options include:

• Dropbox: Upload files to your Dropbox account and share a link with recipients.
• WeTransfer: Send up to 2GB for free without creating an account.
• Google Drive: Gmail automatically converts attachments over 25MB into Drive links.
• iCloud Mail Drop: Apple users can send files up to 5GB through Mail Drop.

These services track downloads, set expiry dates and handle the technical complexity of large file transfers.

Wrapping up

Email size limits protect server performance, prevent security attacks and maintain compatibility across different email providers. Our 20MB limit aligns with industry standards while allowing most common attachments to pass through without issues.

Use file sharing services for anything larger than 20MB. You can access your email anytime through the client area under manage services.

If you run into any trouble, get in touch and our team will be happy to help.