It is proper Netiquette to zip large files before attaching them. Do zip large files.
Zip Netiquette For Email
Large files slow network traffic and computer processors. Zipping a file shrinks the size with a software program. It must be unzipped by the recipient.
Most networks have limits on file sizes. Zipping a file is necessary to deliver large files on networks with restrictions.
Zip large files before attaching them because many networks have limits.