Hi, I have a problem with sending email. I receive emails on my mailbox correctly, but I can't send out email from mailbox. When I try to send message I always get the notification with underneath content:

host relay.dynu.com[168.235.105.136] said: 530 SMTP
authentication is required. (in reply to RCPT TO command).

I have configured my postfix properly in accordance with manual on your site.
I added respectively following entries in my config postfix file (main.cf)

smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous
relayhost = [relay.dynu.com]:2525

I created file /etc/postfix/sasl_passwd and added there the authentication data:
[relay.dnu.com]:2525 relay@relay.grzybjaroslaw.store:my_password

Can you try to solve my problem. I really don't know what I have to do to resolve the issue.

I will be really appreciate for some hints.
Best regards Jaroslaw Grzyb