Are you using Gmail? If so you can easily block emails from people you wish you’d never heard of by using filters. The emails will still be received, but will be automatically deleted.
Once in the trash they will disappear after 30 days. You need never see another email from your unwanted contact. There is a video here to show you how to do it.
You may be sending an email with several attachments. For example you might want to send a Word Document, an Excel Spreadsheet and a photo to a friend. You can attach each file in turn – so in this case you’d be sending three attachments, or you can zip the three files up into one package and send that as a single attachment to your email. The single zipped package of files is sometimes referred to as an archive.