Email servers usually restrict the size of attachments it will send or receive. If your message with attachments are failing to send or receive, use this page to determine if the attachments are too large for email.
The size limit for an email (which includes all attachments) is 50 megabytes (MB) total, which may be too small at times.
There are a few things you can do to get your files to send:
If you upload your file(s) to Microsoft OneDrive you can share the file(s) using a OneDrive link instead of sending it as an attachment. You can specify whether you want the link to allow for editing permissions or not. Files can even be shared with people who are not affiliated with PBS.
A simpler approach can be to split up the attachment(s) you want to send into multiple parts. This would only require you to send them in separate emails, but would not work if you have a single file that is over the size limitation.
One option for compressing files, which will shrink their overall size (the amount the file shrink depends on the files' ability to be compressed, so results may vary), is to "Zip" your file and then attach it to the email. For more information on zipping files, click here.