Should I capitalize "Internet" and hyphenate "e-mail"?
The Internet is a proper noun. In the English language, almost all proper nouns begin with a capital letter. Therefore, when referring to the Internet, a global interconnected network of computers, always capitalize the first letter. It should be noted that the word internetwork refers in general to a network of computers; it does not require capitalization.
Depending on the style guide you or your organization follow this rule may be different. For example, in the Microsoft Manual of Style "Internet" is capitalized. However, in the Associated Press Stylebook "internet" is lowercase.
Short for "electronic mail," the spelling of e-mail is widely accepted as both "e-mail" and "email." However, according to Merriam-Webster and other authorities, the correct spelling is "e-mail" because it is the compound noun of the words "electronic" and "mail." Other style guides like the Microsoft Manual of Style use "email" with no hyphen.
Computer Hope also chooses to use "e-mail" to help prevent confusion with other compound nouns and other words with the "e-" prefix.