What is best way to optimize code and query? - php

Question

I have hundreds of response from php IMAP (fetching email), I wanted to insert all the fetched email into database. Problem is that on server stay time is 40 second (Host provider said to me) and my script is taking more than 40 second. Due to the fetching records and insert queries server returning the following error.
[an error occurred while processing this directive]
Here is Php Code
$imap = #imap_open("{mail.******.com:143/novalidate-cert}", '*****#***.com', '*****');
if(isset($imap)){
$message_count = #imap_num_msg($imap);
$array_mail = array();
if($message_count > 0){
for ($m = 1; $m <= $message_count; ++$m){
//$header = #imap_header($imap, $m);
$header = #imap_rfc822_parse_headers(imap_fetchheader($imap, $m));
$email[$m]['from'] = $header->from[0]->mailbox.'#'.$header->from[0]->host;
$from = $email[$m]['fromaddress'];
$from_email = $email[$m]['from'];
$array_mail[] = $from_email;
if(isset($header->cc)){
$hedCC = $header->cc;
foreach($hedCC as $s){
//echo $s->mailbox.'#'.$s->host.'<br />';
$array_mail[] = $s->mailbox.'#'.$s->host;
}
}
if(isset($header->to)){
$hedTO = $header->to;
foreach($hedTO as $t){
//echo $t->mailbox.'#'.$t->host.'<br />';
$array_mail[] = $t->mailbox.'#'.$t->host;
}
}
}
$i = 0;
if (!empty($array_mail)) {
$insertCount = 0;
foreach($array_mail as $m_){
// INSERT HERE
//echo $m_.'<br />';
$isExistWithID = $this->isExistWithID($user_id,$m_);
$email_err = $this->isValidEmail($m_);
$isValid = 0;
if($email_err == false){
$isValid = 1;
}
if($isExistWithID==0 && $isValid==0){
$insert = $this->pdoConnection->prepare("
INSERT INTO ws_email (
u_id,
we_email,
date_added
)
VALUES(
:u_id,
:we_email,
:date_added
)
");
$insert->bindParam(':u_id', $u_id);
$insert->bindParam(':we_email', $we_email);
$insert->bindParam(':date_added', $date_added);
// Insert Data
$u_id = $_SESSION['USERID'];
$we_email = $m_;
$date_added = date("Y-m-d H:i:s");
if($insert->execute()){
$insertCount++;
}
}
$i++;
}// end foreach
$response['success'] = $insertCount.'Email address(s) fetched successfully.';
}
//echo $i;
//
}else{
$response['error'] = 'No record found';
}
}else{
$response['error'] = 'IMAP does not connect';
}
}//end if error is equal to 0
/************ END NEW 29 SEP *************/
echo json_encode($response, JSON_PRETTY_PRINT);
I tried to optimize the code as i can, but still taking long time and due to this server returning the error.
I would like to request to you kindly guide me how can i optimize it. Thank You.