Cannot send external mail from a new domain address


I have setup a new user in ad with an email address of

All our other users have addresses of *

I have changed the mx records, and added the new recipient policy into exchange etc etc.

I can exchange email internally fine with this user

I can send external email into the address ok, and it arrives. However, when i try to reply to send externally i get the following:-

There was a SMTP communciation problem with the recipoents email server. Please contact your system administrator.
(myserver #5.5.0 smtp;554 < Sender address rejected: Access denied>

Is there something I need to do so that I can get this working please?
Who is Participating?

[Webinar] Streamline your web hosting managementRegister Today

SembeeConnect With a Mentor Commented:
That is not an Exchange message.
Are you sending your email through another server? Is that server configured to accept email from that domain?

If you need something solved ASAP then call Microsoft. This site isn't really suitable for time sensitive problem resolutions as it depends on who visits and what spare time they have. Considering that most visitors are American, you have posted before their day has started and it is the first day back for them after a long weekend, you chances of getting a quick response are quite small.

Run the recipient update service
Simon_BrandAuthor Commented:

I've done that and still get the same error. Any other suggestions please?
Making Bulk Changes to Active Directory

Watch this video to see how easy it is to make mass changes to Active Directory from an external text file without using complicated scripts.

Simon_BrandAuthor Commented:
Hi Experts.

I need to try and get this resolved asap, so I've increased the points to maybe tempt you a bit more...
susanzeiglerConnect With a Mentor Commented:
Have you tried sending tests to multiple external addresses? If so, do you get the same error on all?

You might try stopping and starting the SMTP service if you haven't already done so.

When you set up the MX records, did you create a new host name or set the MX to the actual host name of your server?  If it was a new host name, it is possible that there is a reverse DNS issue.

Simon_BrandAuthor Commented:
The mx record for the has been set to, the same as for the users. As the users are fine, assume there is no issue with that.

Sorry Simon, I need to sort it asap, but it's not impacting yet - didn't want to start alarm bells! - but it will be if I cant sort it over the next few days.
Appreciate your point though!

Re the server config, let me tell you what I've done.

1) Pointed mx record of to
2) Created a user with as the primary address, in the same ad environment as the users. Removed the address ad created during the creation of this user.
3) Amended the default recipient policy to include (but obviously kept as the primary), ticked the "manged by server" box.

As far as my understanding goes that should work shouldn't it?
Thing is, the message you are getting is not an Exchange message. It has been generated by something else.
Therefore what you have done on the server looks fine. You have to look at what path the email messages take when they leave your server.

Yep, that is where I was going with the "have you tried to send to multiple external addresses". The message is being rejected at some point--but are all messages from that recipient (your new mailbox) being rejected or just to this one external mailbox?
Simon_BrandAuthor Commented:
Thanks both - I shall move my search onto the firewall.

Just wanted to be sure I'd done the server bit correctly, and there was nothing I needed to do to the smtp connector or anything.

Split the points - hopw thats ok
All Courses

From novice to tech pro — start learning today.