php-mail 1.4.1-1ubuntu1 (amd64 binary) in ubuntu impish

 PEAR's Mail package defines an interface for implementing mailers under the
 PEAR hierarchy. It also provides supporting functions useful to multiple
 mailer backends. Currently supported backends include: PHP's native mail()
 function, sendmail, and SMTP. This package also provides a RFC822 email
 address list validation utility class.