Tracking My Mailign list

Hey guys…php newibe (ish)

Ive got myself an emailing list that sends to addresses i have in an sql database. It all works great but i was wondering how (or if?!) its is possible to track the people that the email is being sent to and tell if its beign read?

I was subscribed to a free srevice over at and they allow you to seer the percentage of peopel on your list that have read the mail…is this hard to do? how would u go about it?

BTW…im using phpMailer if this makes and difference!

Thansk for your time!

thought i add this here instead of startign a fresh post:
ive started using my mailer to send out to larger numbers…about 60 people now and i get this error:

Warning: fsockopen(): php_network_getaddresses: getaddrinfo failed: Name or service not known in /home/fhlinux199/z/ on line 105

Warning: fsockopen(): unable to connect to in /home/fhlinux199/z/ on line 105

Im assumign i that im overworkign the connection and timing out?!

Whats the solutions do this?!