Hestia welcome emails are not working

Do you know what configuration the domain that was used for the hostname should have?

Does the DNS of the domain that was used as the hotsname have something to do with it?

I have checked port 25 and it is unblocked.

I hope someone can help me

Check the exim mainlog in /var/log/exim or exim4/mainlog

Thanks for the reply!

In log, I get the following.

It does not allow me to access / exim

What does the color blue and the color red mean?
I am new and I hope you can help me.

Thanks.

Are you logged in as root user?