private Properties getMailProperties(final int port) {
        final Properties mailProps = new Properties();
        mailProps.setProperty("mail.smtp.host", "localhost");
        mailProps.setProperty("mail.smtp.port", "" + port);
        mailProps.setProperty("mail.smtp.sendpartial", "true");
        return mailProps;
    }
See
<a href="http://sourceforge.net/tracker/index.php?func=detail&amp;aid=1474700&amp;group_id=78413&amp;atid=553186">...</a>
for discussion about this bug

@throws IOException        on IO error
@throws MessagingException on messaging error
src/test/java/de/gessnerfl/fakesmtp/smtp/SmtpComplianceIntegrationTest.java