email socket closing

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After a heated discussion with our host provider the connection is no longer closing.

But while we are here can anybody explain how a socket can return 'EOF'
I know a socket and a file are basically the same, but where does 'eof' come from.
TA

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A class I use (phpmailer) succesfully opens a mail socket.
[PHP]fsockopen(xxxx. XXXXXXXXXX.co.u k,25,$errno,$er rmsg,10)[/PHP]

Succesfully connected to fsockopen with smtp_conn Resource id #18 
host of the server xxxx.XXXXXXXXXX.co.uk 
the port to use 25 
error number if any 0 
error message if any 
return value 10

immediately afterwards if I check the socket
[PHP]$sock_status = socket_get_stat us($this->smtp_conn);
print_r($sock_s tatus);[/PHP]I get the following

sock_status Array ( [stream_type] => tcp_socket [mode] => r+ 
    [unread_bytes] => 0 [seekable] => [timed_out] => [blocked] => 1 [eof] => 1 )

My question is does the 'EOF' and '0 unread bytes' mean the connection has closed
because the writer of the class thinks so.
The email has worked fine for two years but started to fail yesterday
because the 'EOF' is returning '1'
I have no idea what was being returned before because I have just used this class blindly with great success.
Anybody know what is happening?