When your email is rejected due to its size, it is not the attachment size alone thats causing the issue.

Each message contains some overhead, such as the encoding to convert the attachment to text when sent, then back to its original form when received.

This standard uses base64 encoding to convert binary into 7-bit ASCII.

Meaning, a 20MB document on disk exceeds a 25MB file attachment limit.

So that, the largest email attachment size allowed here at the Institute is more like 15MB.

For files under 15MB, you are guaranteed that it will go through the IAS email systems without problems.

That is 60MB. This means that when the mail message is received by the server, which must be under 17MB and it expands a compressed file (like a zip or tar), the size of any individual file uncompressed must be under 60MB.

This limit will aid in the efficiency of email scanning to provide protection from spam and virus infections.

Imagine if a zip or tar had many files that expanded to 100MB each; this would bog down the scanning server.

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Information on how to use or access your personal web directory may be found here.

Cant send Outlook.com emails You might be exceeding these limits.

A former freelance contributor who has reviewed hundreds of email programs and services since 1997.

Like all email providers, Outlook.com puts a limit on a number of email-related things.

Theres a per-email file attachment size limit, a per-day sent email limit and a per-message recipient limit.

However, these Outlook.com email limits are not unreasonable.

The size limit when sending emails with Outlook.com is calculated not only by the size of the file attachments but also by the size of the message, like the body text and any other content.

Email size limits for Outlook.com are in place to reduce the potential of spam.

The total size limit when sending an email from Outlook.com depends on whether you attach a file stored on your computer or a file stored on OneDrive.

If the file is stored on your computer, the attachment size limit is 34 MB; for a OneDrive file, the attachment size limit is 2 GB.

In addition to the message size, Outlook.com limits the number of emails you can send per day to 300 and the number of recipients per message to 100.

Once you establish credibility with the Outlook.com system, these restrictions will be removed and your account will be upgraded to the standard sending limits.

When you send large files and photos with Outlook.com that exceed the available size limit, youll be prompted to first upload the files to OneDrive.

This makes it easier for Outlook to send the file and ensures that the recipient is not restricted by their email services size limits.

Another option to send large files is to first upload the files to a cloud storage service like Dropbox, Google Drive, or OneDrive.

Sharing files via OneDrive enables you to send larger files and collaborate with others in real time on those files.

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If you want to send something even bigger, either email the files in small chunks, make a compressed ZIP file of the attachments, store the files online and share download links to them, or employ another file sending service.

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