Understanding Email Attachment Size Limits in Office 365

    In our Office 365 environment, it's important to be aware of the limitations when sending and receiving email attachments. The maximum size for an email message, including all attachments, is 25 megabytes (MB). This ensures smooth communication while keeping our systems efficient.

   However, it's important to consider that our file size limitations of 25MB might not be the same as those you're trying to send the content. Some entities might have file size limitations less than 25MB, while others might be larger. So if a recipient's email system is rejecting an email for a reason similar to, "Message Size Violation," consider using OneDrive to share the file instead of email.

    Should you need to send a file larger than 25MB, we recommend considering alternative methods such as utilizing cloud storage services like OneDrive. This platform allow you to upload and share larger files easily, providing a seamless experience for both the sender and recipient.

To share large files using OneDrive:

• Upload the File: Sign in to your Office 365 account and navigate to OneDrive. From there, you can upload the file you want to share by clicking Add New on the top-left of the site.

• Generate a Share Link: Once the file is uploaded, right-click on it and select the option to share (or click the share icon. This will generate a link that you can send to the recipient.

• Adjust Permissions (if necessary): You can choose whether the recipient can edit or only view the file. You can also set an expiration date for the link. In the below screenshot, clicking "Anyone with the link can edit" will allow you to declare who gets to view the file, who can edit the file, etc. Clicking "Apply" will update the permissions of that share so that you can then click "Copy Link" (shown in the 1st screenshot below) and add the link into your email. You can also type a quick message and email targets within this area as well, which is handy if you're sharing large files with a specific individual instead of a group of people.

• Send the Share Link via Email: Compose a new email and paste the share link directly into the body of the message. This way, the recipient can simply click on the link to access and download the file if you've made it publicly accessible. Again, don't set it to where anyone can access the file, if the content contains private or personal information.

Note: To reinforce for the sake of privacy and security, never share files with others that might include personal or private information of others to parties that are not intended to receive them. Practice due diligence with ensuring your shares are properly configured so that others cannot retrieve the data you're intending for specific parties.

Alternative: If your file is barely larger that 25MB, consider trying to Compress to ZIP file, and attaching the ZIP file instead. In Windows 10, you right-click the file and Send To -> Compressed (Zipped) Folder. Windows 11 can handle this as well, but it looks slightly different. This might give you an edge to where your content can be compressed smaller than 25MB, and still get the file attached to an email!

    Using OneDrive for Business in this manner not only allows for the easy transfer of large files but also ensures that your email messages stay within the specified size limits.