Exchange 2016 Eail Stuck i Unreachable Queue

Exchange 2016 CU 10 DAG  2 Nodes

I am getting emails stuck in the  Unreachable Queue


Open in new window is not a mailbox on my exchange server but I tried to create one and it says it already exists.

any ideas?
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Thomas GrassiSystems AdministratorAsked:
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timgreen7077Exchange EngineerCommented:
your screenshot is empty. it may be a distribution list or contact.
Thomas GrassiSystems AdministratorAuthor Commented:


I just removed them when they come back I will post it again

I only have three (3) distribution groups and none have that address.

I do not have any contacts listed.

Any command I can run to check the email address?
timgreen7077Exchange EngineerCommented:
You can run the below to try and find that email address:

Get-Recipient -ResultSize unlimited | where {$_.emailaddresses -eq ""} | fl name, emailaddresses
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Thomas GrassiSystems AdministratorAuthor Commented:

Thanks for the command

[PS] C:\Windows\system32>Get-Recipient -ResultSize unlimited | where {$_.emailaddresses -eq ""} | fl
name, emailaddresses

Name           : Support
EmailAddresses : {X400:C=us;A= ;P=TGCSNET;O=Exchange;S=Support;,}

So why do I not see it in the list of mailboxes?


From my outlook client I sent a test email and it bounced back
10/23/2018 4:02:07 AM - Server at returned '550 4.4.7 QUEUE.Expired; message expired in unreachable destination queue. Reason: There is currently no route to the mailbox database.'
Original message headers:
Received: from ( by ( with Microsoft SMTP Server
 (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id
 15.1.1531.3; Sat, 20 Oct 2018 23:50:43 -0400
Received: from
 ([fe80::15aa:fcea:e256:46d3]) by
 ([fe80::15aa:fcea:e256:46d3%4]) with mapi id 15.01.1531.007; Sat, 20 Oct 2018
 23:50:43 -0400
Content-Type: application/ms-tnef; name="winmail.dat"
Content-Transfer-Encoding: binary
From: "Thomas R. Grassi Jr" <>
To: Support <>
Subject: test
Thread-Topic: test
Thread-Index: AdRo8TSZuf2RtcT8RNqGjX/WcZ3YcA==
Date: Sat, 20 Oct 2018 23:50:42 -0400
Message-ID: <>
Accept-Language: en-US
Content-Language: en-US
X-MS-TNEF-Correlator: <>
MIME-Version: 1.0
X-Originating-IP: []

Open in new window

timgreen7077Exchange EngineerCommented:
delete that address from your outlook client auto-complete cache.

also do you have a single domain, or do you have a parent (root) and child domain?
Thomas GrassiSystems AdministratorAuthor Commented:

The email is coming from my nagios server

I just tried to send a test via my outlook to see the results

I need to remove this from my exchange server

Yes I have 3 domains all trusted one is a child domain

The nagios server is on the parent domain

How can I get rid of the address then I would like to recreate it
timgreen7077Exchange EngineerCommented:
If that email is coming from a server, you will need to access that server and remove the settings on that server that is sending that email. That part is not an exchange issue. Run the following:

Set-ADServerSettings -ViewEntireForest $true

Next run this recreated cmdlet and it will show you what OU the object is located in your AD environment so that you can remove it or what ever you choose:

Get-Recipient -ResultSize unlimited | where {$_.emailaddresses -eq ""} | fl name, emailaddresses, OrganizationalUnit, RecipientType, RecipientTypeDetails
Thomas GrassiSystems AdministratorAuthor Commented:

I looks like a public folder

[PS] C:\Windows\system32>Set-ADServerSettings -ViewEntireForest $true
Creating a new session for implicit remoting of "Set-ADServerSettings" command...
[PS] C:\Windows\system32>Get-Recipient -ResultSize unlimited | where {$_.emailaddresses -eq ""} | fl
name, emailaddresses, OrganizationalUnit, RecipientType, RecipientTypeDetails

Name                 : Support
EmailAddresses       : {X400:C=us;A= ;P=TGCSNET;O=Exchange;S=Support;,}
OrganizationalUnit   : Exchange System Objects
RecipientType        : PublicFolder
RecipientTypeDetails : PublicFolder

Can I just delete that public folder by removing it from the ad ou?  or do I need the command on exchange.

Once I delete that public folder I should be able to create the mailbox  with that email address.

I believe that is from my old exchange 2010 setup  

What is the proper way to remove them?
timgreen7077Exchange EngineerCommented:
no you need to remove the public folder from the exchange. just access the Exchange admin center and delete that public folder or remove the email address from the public folder. once that is done, yes you can create a mailbox with that email address if you choose to.
timgreen7077Exchange EngineerCommented:
if this was from your old 2010 environment then you will need to use ADSIEdit. see link below for help with removing public folder via adsiedit. if this public folder doesnt exist anymore and isnt in your 2016 environment you will need to use adsiedit but be sure because that is always the last resort.
Thomas GrassiSystems AdministratorAuthor Commented:

Yes I have no public folders yet on my 2016 environment

Using Adsiedit    see attached.

they are in AD in the OU tho
timgreen7077Exchange EngineerCommented:
oh ok.
timgreen7077Exchange EngineerCommented:
go into the EAC and under mailboxes select the ellipses (...) and go to advanced search, and select email addresses and enter the email address and see if it shows up via that search.
Thomas GrassiSystems AdministratorAuthor Commented:

I found in the Nagios server where it was using I changed  it to a valid account now

But I would still like to be able to remove these public folders
Thomas GrassiSystems AdministratorAuthor Commented:

I did the advanced search and did not find the address
timgreen7077Exchange EngineerCommented:
you should be able to delete those files since they are no longer in your environment, but I'm hesitant to tell you to delete them since I really dont know your environment so that is a choice you will need to make. good as I mentioned earlier about changing that email on that server.

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Thomas GrassiSystems AdministratorAuthor Commented:

I made the change on the Nagios server now.

My environment is Windows 2012 R2 Domain Controllers  

Should I just delete all the old 2010 public folder from AD?
timgreen7077Exchange EngineerCommented:
you can but that is up to you. it seems that those public folders are gone so yes you should be fine, but I leave that part to you.
Thomas GrassiSystems AdministratorAuthor Commented:

All good now
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