Microsoft Exchange 2019 SMTP Connector , Linux exim4 SmartHost

Hi everyone,
My mother tongue is not English. Therefore, I may not be able to express myself correctly, I expect some understanding from you on this matter.

I’m using Microsoft Exchange 2019. I created “send connector” by following the document below.

http://www.authsmtp.com/exchange-2019/exchange2019_setup.html

Exchange server side settings are exactly the same as above.

On Ubuntu 20.04, I installed hestiacp with the following installation script. Could you please check?

sudo bash hst-install.sh --apache no --phpfpm no --multiphp no --vsftpd no --proftpd no --named no --mysql no --postgresql no --exim yes --dovecot no --sieve no --clamav yes --spamassassin yes --iptables no --fail2ban yes --quota no --api yes --interactive yes --with-debs no --port 8083 --hostname smtp.example.org --email [email protected] --password 123456789 --lang en

Then, following the document below, I added 1 domain name that already exists in Exchange server 2019, using hestiacp command line or gui.
httpZ://docs.hestiacp.com/cli_commands/commands.html#v-add-mail-account

v-add-mail-domain-smtp-relay user domain.tld exchangesrv.domain.com User1 Pass12345

What I want to do is this?
I want to add domains from Exchange server to hestiacp. I want domain.tld on the Exchange server to send out emails (hotmail, yahoo, gmail, etc.) via Exim4.

But the emails I send from OWA are eg hotmail, yahoo, gmail etc. does not reach . What could be the problem?

I can access all ports from Exchange server to Linux hestiacp (Exim4). Both servers can access the internet. But I can’t send emails this way.

On the Exchange server, "basic authentication (username, password) has been defined in the send connector definition. ( User1 Pass12345 )

What am I missing or doing wrong?

Hello again.
I want to add some domains existing on Exchange server to ubuntu exim4 (hestiacp server). These domains allowed in exim4 should be able to send correct emails to the internet.

On the hestiacp side, I don’t want anything like antispam/antivirus scanning of incoming emails and sending them to the exchange server. What I want to do is just send outgoing email from exchange server using linux MTA