Email attachment size limits explained

Sending a large file by email can result in the message being rejected before it reaches the recipient. Knowing the size limits that apply to your email account helps you avoid failed deliveries and find the right tool for the job.

Email attachment size limits

The maximum size for a single email message, including all attachments, is 50MB. This applies to messages you send and receive through your UWH email account.

It is worth knowing that the 50MB limit covers the entire message, not just the attached files. Email encoding adds overhead to attachments, so a 40MB file may push the total message size over the limit once encoded. Keeping attachments well below 40MB gives you a safe margin.

Many internet service providers and corporate mail servers impose their own limits, often as low as 20MB. Even if your outgoing message is within the 50MB limit, the recipient’s mail server may still reject it. For reliable delivery, keep attachments as small as possible.

Sending large files without email

Email was not designed as a file transfer protocol. When you need to share files that are too large to attach, a dedicated file sharing service is a more reliable option. The recipient receives a download link rather than an attachment, which avoids mail server limits entirely.

Common options include:

• WeTransfer – free transfers up to 2GB with no account required
• Google Drive – share files of any size via a link
• Microsoft OneDrive – integrated with Outlook and Microsoft 365
• Dropbox – suitable for ongoing file sharing with clients or colleagues

Upload the file to your chosen service, then paste the share link into your email body. The recipient downloads the file directly, bypassing mail server restrictions.

Wrapping up

Email messages on UWH hosting have a maximum size of 50MB, including all attachments. Because many receiving mail servers apply lower limits, keeping attachments under 20MB gives the best chance of successful delivery.

For larger files, a cloud sharing service is the most dependable approach. If you are experiencing other email issues, see our guides on email blocked for spam and creating an email account for related help.