To avoid this either Manually add line breaks every so often. Configure your mailer to do this for you. An email address the message is to be copied to. You can enter your own email address, though it is normal to use the options of the email package to state if you always want a copy of outgoing messages. When adding attachments you will normally be asked for the name of the file to attach.
Encoding is a way of splitting files into text that is safe to pass through the email system.
Binary files have to be encoded. Some mail readers cannot process attachments. This won't be an option for binary files. How mail gets to you depends on what type of internet access you have. If you work for a large organisation you probably have a permanent connection to the internet, and mail will simply arrive in your inbox.