Question

an email address must contain one and only one ________​

Answer 1

Answer:

Technically single quotes are allowed in e-mail addresses: RFC 5322 - Internet Message Format and exemplified by Email address syntax on Wikipedia ; and you could substitute a single quote for an apostrophe. However single quotes delimit strings in many programming languages

Answer 2

Explanation:

Every email address has two main parts: a username and domain name. The username comes first, followed by an at (@) symbol, followed by the domain name. In the example below, "mail" is the username and "techterms.com" is the domain name