smtp;550 sorry, no mailbox here by that name. (#5.1.1)


We are using Exchange 2010 RU 6. We created new Mail account (new mailbox) when we try to send mail to this mail not from our domain (like to send from iCloud/Gmail etc) we getting immediately mail back:

 Message-id: <>
 Date: Wed, 29 May 2013 14:48:18 +0200
 From: me at iCloud <>
 To: Mail to name<>
 Subject: Test

Your message cannot be delivered to the following recipients:

 Recipient address:
 Reason: Remote SMTP server has rejected address
 Diagnostic code: smtp;550 sorry, no mailbox here by that name. (#5.1.1)
 Remote system: ns;mrx.OurDomain.comTCP|nn.nnn.nnn.nnn|48628||25) (Ready to receive mail -=- ESMTP)

When the mail sent from the domain it self to the new mailbox all works perfect (i.e. send mail from

I looked over here and nothing that helped to fix this issue.

Any ideas?
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Simon Butler (Sembee)Connect With a Mentor ConsultantCommented:
I would be looking at that as the cause, check whether it has any kind of recipient validation list that needs to be updated. If it uses a live LDAP lookup then check it is working correctly. It could be that whatever server it is using isn't getting the new information.

Jeffery HayesSystem Support Technician Commented:
Couple be a co-existence issue and may need the MX records to be updated for the domain.

Check the SMTP Receive Logs  along with message tracking logs.

Likewise can the new mailbox send external mail to you and can you reply to it?

If your environment has lotus notes mailbox as well this might be binary tree needs to be updated.
ym1Author Commented:
Thanks for the replay.

The new mailbox can send mail to the external mail but on replay it gives the same error.

By checking the MX record it looks fine.

To clear one point all exists mails (100's mail boxes) are working perfect just new created mailbox gives the error I try to create few and all gives the same error.
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Simon Butler (Sembee)ConsultantCommented:
That error message is not an Exchange error, it is coming from something else.
Is there something between Exchange and the internet?

In the NDR, where it says remote system, does that correspond with something you recognise?

ym1Author Commented:
Yes we have the Pineapp (Anti virus/Spam) server
ym1Author Commented:

Thanks, as you wrote the live LDAP lookup didn't work new mailbox didn't updated, by adding the mailbox manually the problem solved and now I will have to fix the live LDAP lookup.
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