The eregi function will be replaced by preg_match in future versions of php if you are receiving a depreciated function warning when using Modx WebLoginPE then scroll down to line 2920 of your webloginpe.class.php file and replace the line with this snippet of code:
if (!preg_match("/^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,6}$/i", $Email))