Word document is too large to email

Turn on Mail Drop. Add an email attachment in Mail on iCloud.com - Apple Support

that will allow you to send files that exceed mailbox limits in email.

Your ISP has invoked a limitation on your outgoing email attachment size. Open that Word document in MS Word and on the File menu, use Reduce File Size… and save to a new document. Compare the sizes, and if the difference is significant, try emailing the revised document.

An alternative might also be to open that Word document in LibreOffice Writer and resave it. I just did that with a 311KB Word document saved from Word v16.62, and the resulting file saved from LibreOffice was 201 KB.