Error creating table: Incorrect table name - php

Question

I cannot access the textbox content to create the table in Mysql and the error is
"Error creating table: Incorrect table name ''
<?php
$conn=mysqli_connect("localhost","root","","abc");
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$email = isset($_POST['email']) ? $_POST['email'] : '';
// sql to create table
$sql = "CREATE TABLE `$email` (
`id` INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
`firstname` VARCHAR(30) NOT NULL,
`lastname` VARCHAR(30) NOT NULL,
`email` VARCHAR(50),
`regdate` TIMESTAMP
)";
if ($conn->query($sql) === TRUE) {
echo "Table MyGuests created successfully";
} else {
echo "Error creating table: " . $conn->error;
}
$conn->close();
?>

Answer 1

If error is "Error creating table: Incorrect table name" and you query has:
CREATE TABLE `$email`
Most probably $email has an # sign in it, that shouldn't be part of a table name - use only [0-9,a-z,A-Z$_] (basic Latin letters, digits 0-9, dollar, underscore).
It is not likely that a table should be created each form sublimation, and that its name should be dynamic (you will not know it to query data from this table).
Not less important - never use user input directly in your SQL (to avoid SQL injection). Reference:
PHP MySQLi Prepared Statements Tutorial to Prevent SQL Injection

Answer 2

You can try as follows-
$email = $_POST['email'];
// sql to create table
$sql = "CREATE TABLE IF NOT EXISTS $email(
`id` INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
`firstname` VARCHAR(30) NOT NULL,
`lastname` VARCHAR(30) NOT NULL,
`email` VARCHAR(50),
`regdate` TIMESTAMP
)";