php mail problem on lycos

[anuragshr]

Hi,
Facing a very serious problem. I am sending mail thru php when i send mail on yahoo or hotmail its works fine...my code is like this
<?php
echo("**");
$header = "From: [e-mail] \r\n";
$header = $header."Content-Type: text/html\r\n";
$rt = mail("[e-mail]", "to lycos test2", "to lycos test2", $header);
echo("$rt************************");
?>
but when i want to send mail on lycos account and change [e-mail] to [email][e-mail]..noth[/email]ing happen and i didnt get mail.
Please help.
Regards
Anurag