Hi..
In Hp ux box,, mails are not being sent. they are getting queued up in mail queue.
Is the mailer daemon running, and has it been configured? man sendmail...
The sendmail daemon does not need to be running in order to send mail. Only to recieve or process the queue.
Test the email manually.
/usr/sbin/sendmail -v someone@mycompany.com
this is a test
<ctrl-d>
The above will verbosly show you what is happening to your email. Common failures. DNS lookups or destination not accepting due to some reason.
Post some output.
you are correct, an active deamon is only required if you want this server to receive mail.
but the configure part is necessary 