A simple class that creates an Exchange mailbox using the LdapRecord package

MailboxFactory.php

<?php

use Illuminate\Support\Str;
use LdapRecord\Models\ActiveDirectory\Entry;
use LdapRecord\Models\ActiveDirectory\User as LdapUser;
use LdapTools\Security\GUID;
use Ramsey\Uuid\Uuid;

class MailboxFactory
{
    protected $configurationDn;

    public function createMailbox()
    {
        // Use your organizational unit (OU)
        $ldapUser = (new LdapUser)->inside('OU=Staff,DC=local');

        $email = 'john.doe@example.com';
        $username = 'john.doe';

        // Populate these values
        $ldapUser->givenName = 'John';
        $ldapUser->sn = 'Doe';
        $ldapUser->cn = 'John Doe';
        $ldapUser->displayName = 'John Doe';
        $ldapUser->name = 'John Doe';
        $ldapUser->title = 'Employee';
        $ldapUser->department = 'Department';
        $ldapUser->manager = 'CN=Boss Man,OU=Staff,DC=com';
        $ldapUser->unicodePwd =  Str::random();
        $ldapUser->samaccountname = $username;
        $ldapUser->mailNickname = $username;
        $ldapUser->mail = $email;
        $ldapUser->userPrincipalName = $email;
        $ldapUser->company = 'Company Name';
        $ldapUser->streetAddress = '123 Main Street';
        $ldapUser->l = 'City';
        $ldapUser->st = 'ST';
        $ldapUser->c = 'Country';
        $ldapUser->postalCode = '123456';
        $ldapUser->wWWHomePage = 'https://www.example.com';
        $ldapUser->telephoneNumber = '123-123-123';

        // Exchange attributes
        // The logic was ported from LdapTools
        $ldapUser->msExchHomeServerName = $this->getExchangeServerDn();
        $ldapUser->legacyExchangeDN = $this->getLegacyExchangeDn($username);
        $ldapUser->homeMDB = $this->getExchangeDatabaseDn();
        $ldapUser->mDBUseDefaults = 'TRUE';
        $ldapUser->msExchUserCulture = 'en-US';
        $ldapUser->proxyAddresses = "SMTP:{$email}";
        $ldapUser->msExchMailboxGUID = (new GUID(Uuid::uuid4()))->toBinary();
        $ldapUser->msExchUserAccountControl = 0;
        $ldapUser->msExchRecipientDisplayType = 1073741824;
        $ldapUser->msExchRBACPolicyLink = $this->getExchangeRbacPolicyDn();
        $ldapUser->msExchRecipientTypeDetails = 1;
        $ldapUser->msExchVersion = 88218628259840;
        $ldapUser->showInAddressBook = $this->getAddressBookDns();
        $ldapUser->msExchPoliciesIncluded = $this->getRecipientPolicyDn();

        // Save the user initially
        $ldapUser->save();

        // Enable their account
        $ldapUser->userAccountControl = 512;
        $ldapUser->save();

        // Force password reset when the log in
        $ldapUser->pwdlastset = 0;
        $ldapUser->save();

        return $this;
    }

    protected function getExchangeServerDn()
    {
        if (!$this->configurationDn) {
            $this->getConfigurationNamingContext();
        }

        $exchangeServer = Entry::in($this->configurationDn)
            ->where('objectclass', 'msExchExchangeServer')
            ->whereHas('serverrole')
            ->first();

        if (!$exchangeServer) {
            throw new \Exception("Exchange server not found.");
        }

         return $exchangeServer->getFirstAttribute('distinguishedname');
    }

    protected function getExchangeDatabaseDn()
    {
        if (!$this->configurationDn) {
            $this->getConfigurationNamingContext();
        }
        
        // This is the name of your Exchange mailbox database
        $database = 'Mailbox-Db-Name';

        $exchangeDb = Entry::in($this->configurationDn)
            ->where('objectclass', 'msExchMDB')
            ->where('cn', $database)
            ->first();

        if (!$exchangeDb) {
            throw new \Exception("Exchange database not found.");
        }

        return $exchangeDb->getFirstAttribute('distinguishedname');
    }

    protected function getExchangeRbacPolicyDn()
    {
        if (!$this->configurationDn) {
            $this->getConfigurationNamingContext();
        }

        $rbacPolicy = Entry::in($this->configurationDn)
            ->where('objectclass', 'msExchRBACPolicy')
            ->where('cn', 'Default Role Assignment Policy')
            ->first();

        if (!$rbacPolicy) {
            throw new \Exception("Exchange RBAC policy not found.");
        }

        return $rbacPolicy->getFirstAttribute('distinguishedname');
    }

    protected function getAddressBookDns()
    {
        if (!$this->configurationDn) {
            $this->getConfigurationNamingContext();
        }

        return Entry::in($this->configurationDn)
            ->where('objectclass', 'addressBookContainer')
            ->get()
            ->filter(function ($addressBook) {
                return in_array($addressBook->getFirstAttribute('cn'), [
                    'All Mailboxes(VLV)',
                    'All Recipients(VLV)',
                    'All Users',
                    'Default Global Address List',
                    'Mailboxes(VLV)',
                ]);
            })
            ->pluck('distinguishedname')
            ->flatten()
            ->toArray();
    }

    protected function getRecipientPolicyDn()
    {
        if (!$this->configurationDn) {
            $this->getConfigurationNamingContext();
        }

        $policy = Entry::in($this->configurationDn)
            ->where('objectclass', 'msExchRecipientPolicy')
            ->where('cn', 'Default Policy')
            ->first();

        if (!$policy) {
            throw new \Exception('Recipient policy could not be found');
        }

        return $policy->getFirstAttribute('distinguishedname');
    }

    protected function getLegacyExchangeDn(string $username)
    {
        if (!$this->configurationDn) {
            $this->getConfigurationNamingContext();
        }

        $policy = Entry::in($this->configurationDn)
            ->where('objectclass', 'msExchAdminGroup')
            ->first();

        if (!$policy) {
            throw new \Exception('Recipient policy could not be found');
        }

        $uuid = str_replace('-', '', Uuid::uuid4());

        return $policy->getFirstAttribute('legacyexchangedn')
            . "/cn=Recipients/cn={$uuid}-{$username}";
    }

    /**
     * Gets the configuration naming context from the root dse
     *
     * @return $this
     */
    protected function getConfigurationNamingContext()
    {
        $rootdse = Entry::in(null)
            ->read()
            ->whereHas('objectclass')
            ->first();

        $this->configurationDn = $rootdse->getFirstAttribute('configurationnamingcontext');

        return $this;
    }
}