I have my domain pointing to the ns and the site works well. The thing is my domain is with some other org anization and the mail server too. I have edited the mx entries to point to the new mails but nothing seems to be working. An mx lookup shows the entries as they should be. What could be wrong?
You might want to list the domain name, so others can do lookups. Most that answer here are other customers, so information such as that is needed to really be able to help. If you can’t tell us the domain name then you might want to open a support ticket and get them to look.
554 is common when the outgoing mail server requires authentication and the client (outlook, thunderbird, etc) has not been configured correctly.
So where do you think the problem is? I would expect the email to be delivered to the server even if the client is not configured right. Or what is the normal steps?
in the old days the original internet mail concept was that smtp (the outbound server) would accept all mail from any user, but spammers abused that.
Today most all smtp servers require authentication. Including dreamhosts. However, you said you are forwarding your mx records elsewhere, so you will need to check there and find out how to set you outgoing or smtp server settings. I suspect the problem is you have not yet set that part up.
are you able to receive mail correctly? by post #3 here i’m making the assumption that your problem is sending and not receiving.