php install

[Robert Munn]

I have installed PHP 5.2.5 with the following configuration line on a 
5.5-Stable system

./configure '--with-apxs2' '--with-gd' '--with-mysql' 
'--with-jpeg-dir=/usr/local/lib' '--with-zlib-dir=/usr/local/lib' 
'--with-freetype-dir' '--enable-sockets'

The installation proceeds flawlessly.  When my application tries to send 
smtp mail to gmail on port 465 I get the following message

Warning: stream_socket_client(): unable to connect to 
tls://smtp.gmail.com:465 (Un
able to find the socket transport "tls" - did you forget to enable it 
when you con
figured PHP?) in PHP5/SMTP5.php on line 129

Informative but not very helpful.  Can anyone tell me how I enable "tls"?

With  thanks in advance

Robert Munn