Verify Email accuracy using PHP

Please contact me with any Title: http://www.webjx.comweb @ webjx.com reprinted please indicate the source when you registered on a forum, usually have an e-mail address verification function, when you enter an illegal pattern will present some kind of error prompt letter what title please contact me: http://www.webjx.com web@webjx.com
Reprinted please indicate the source

When you register on a forum, there is usually an e-mail address verification function. when you enter an illegal pattern, an error message is displayed.

We can apply the following rule expression
Ereg ('^ [a-zA-Z0-9 _] @ [a-zA-Z0-9 \-] \. [a-zA-Z0-9 \-\.] $]', $ email );

However, the above sub-statement only checks strings and does not support output. We can further use this formula to return information:
If (eregi ('^ [a-zA-Z0-9 _] @ [a-zA-Z0-9 \-] \. [a-zA-Z0-9 \-\.] $]', $ email ))
{
Return FALSE;
}

Next we can further check whether the host name exists:
List ($ Username, $ Domain) = split ('@', $ email );
If (getmxrr ($ Domain, $ MXHost ))
{
Return TRUE;
}
Else
{
If (fsockopen ($ Domain, 25, $ errno, $ errstr, 30 ))
{
Return TRUE;
}
Else
{
Return FALSE;
}
}

Now let's organize the above two functions with PHP to form a function:
Function checkEmail ($ email)

{If (eregi ('^ [a-zA-Z0-9 _] @ [a-zA-Z0-9 \-] \. [a-zA-Z0-9 \-\.] $]', $ email ))
{
Return FALSE;
}

List ($ Username, $ Domain) = split ('@', $ email );

If (getmxrr ($ Domain, $ MXHost ))
{
Return TRUE;
}
Else
{
If (fsockopen ($ Domain, 25, $ errno, $ errstr, 30 ))
{
Return TRUE;
}
Else
{
Return FALSE;
}
}
}

Then we can use this function to check whether an input Email exists. for example:

If (checkEmail (web@webjx.com) = FALSE)
{
Echo 'The input E_mail is inaccurate .';
}
Else
{
Echo 'input E_mail is accurate .';
}