So I have enabled an Ubuntu Server 20 in the cloud with a dedicated public IP, and I want to use it as a SMTP server for MyDomain.com. I have setup DNS and PTR, so this server is mail.MyDomain.com
I have installed Postfix 3.4.13. Then I have created a user with adduser jack
So now, if I login with putty (SSH) to the server as jack, I can succesfully send mails with echo "test" | sendmail Anyone@hotmail.com
The problem is when I am remotely trying to send mail from my laptop (remote network). I can telnet mail.MyDomain.com 25
and send a EHLO command but when I try to use Outlook, I get error
None of the authentication methods supported by this client are supported by your server
Outlook config is:
- SMTP Server: mail.MyDomain.com
- user: jack
- pass: JacksPassw@rd
- port: 25
- No Encryption
I've read something about SASL authentication, Dovecot or Cyrus, but I honestly have no idea about this services, nor I'm sure if it's neccesary in a Send Only Email server, as I'm not going to have any incoming mail handled. Our MailBoxes are in a different Server.
What will be the most straightforward way of authenticating as "Jack" from my local Outlook client?? By default, when installing PostFix in Ubuntu, TLS has been enabled, so I wouldn't mind using these as well:
smtp_tls_CApath = /etc/ssl/certs
smtp_tls_security_level = may
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache