Create domain alias

Question

I created domain alias using the following LDIF sentences:
A:
dn: dc=b, dc=a, dc=com, dc=cn, o=internet
changetype: add
objectclass: alias
objectclass: inetDomainAlias
aliasedObjectName: dc=x, dc=y, dc=com, o=internet
dc:b
Later, I also tried B::
dn: dc=b.a.com.cn, o=internet
changetype: add
objectclass: alias
objectclass: inetDomainAlias
aliasedObjectName: dc=x, dc=y, dc=com, o=internet
dc:b.a.com.cn
it seemed both works.
I wonder which way is right?
or, when should I use which?
thanks.

Answer 1

Let me clarify over the previous clarification:
my goal:
A. When users send emails to internal addresses
([email protected] and [email protected]), the senders' addresses
should be looks like [email protected] or
[email protected] at the recipients' mailboxes, in
another word, the "from" section of the email.
And,
B. When users send emails to external addresses
including [email protected] and other
address, e.g. [email protected], "from" sections of
senders' emails should be like [email protected], or
[email protected]
That is, users from the Internet will only see the [email protected]/[email protected] address.
>
So,
What I am thinking is:
1. apply rewrite rule at tcp_local to rewite the
"from" section of emails sent to the Internet
2. create domain alias b.a.com.cn and c.b.a.com.cn
for x.com and y.x.com respectly.
So emails sent to [email protected]/[email protected] will be delivered to [email protected]/[email protected]
>
I do not think I need to add mailalternateaddress to
each user's defination in ldif. Right?
Would this work?
Thanks.Thank you.