Recipients can be added in three ways: addTo(): Adds a recipient to the mail with a "To" header addCc(): Adds a recipient to the mail with a "Cc" header addBcc(): Adds a recipient to the mail not visible in the header getRecipients() serves list of the recipients. clearRecipients() clears the list. addTo() and addCc() accept a second optional parameter that is used as a human-readable name of the recipient for the header. Double quotation is changed to single quotation and angle brackets to square brackets in the parameter. All three of these methods can also accept an array of email addresses to add instead of one at a time. In the case of addTo() and addCc(), they can be associative arrays where the key is the human readable name for the recipient.