I have been considering replacing fsockopen with imap_ functions to cater for a pop3-web interface. This is initially for 3 clients. While all 3 allow connection and functionality with fsockopen, only 2 of the 3 will allow me to use imap_open()

Code snippets for the failed connection is:
PHP Code:
$server1 "{xx.xx.xx:110/pop3}INBOX";
$mbox imap_open($server$user$pass)
    or die(
"can't connect: " imap_last_error());
This supplies the error:
Warning: imap_open(): Couldn't open stream {xx.xx.xx:110/pop3}INBOX in /home/dundee/public_html/testing/imap_pop3.php on line 50
can't connect: Can not authenticate to POP3 server:
The username and password combinations are fine, i have checked them also through telnet and there are no authentication problems there.