nextcloud-mail2deck/lib/MailClass.php

<?php

class MailClass {
    private $inbox;

    public function __construct()
    {
        $this->inbox = imap_open("{" . MAIL_SERVER . ":" . MAIL_SERVER_PORT . MAIL_SERVER_FLAGS . "}INBOX", MAIL_USER, MAIL_PASSWORD)
        or die("can't connect:" . imap_last_error());
    }

    public function __destruct()
    {
        imap_close($this->inbox);
    }

    public function getNewMessages() {
        return imap_search($this->inbox, 'UNSEEN');
    }

    public function fetchMessageStructure($email) {
        return imap_fetchstructure($this->inbox, $email);
    }

    public function fetchMessageBody($email, $section) {
        return imap_fetchbody($this->inbox, $email, $section);
    }

    public function headerInfo($email) {
        return imap_headerinfo($this->inbox, $email);
    }

    public function reply($sender, $response) {
        $to = $sender->mailbox . '@' . $sender->host;
        mail($to, 'your card has been created', 'card/board link.....');
    }
}