Do you run from a vps you rent ?This is the tutorial I used when I did it 2 years ago :
It's really complete.
dude i have tried no luck?Did you follow the guide I provided or another guide? The guide I provided shouldn't give you errors, it's the only guide that I could just copy and paste the commands without thinking and having a functional mailserver...
Dude, cause you didn't read. There's no place in this guide that tells u to use "sudo /etc/hosts" because it isn't a valid command. If you look and read the guide correctly, you would have seen that the exact command is "nano /etc/hosts".
I strongly recommend that if you can't setup your own mailserver to just buy a service that offers it.can you setup plz ? the management of it we're fine with just setup we struggle