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Go through checklist provided below by Exchange deployment assistant (Ex 2010 to 2016)<br />
<br />
<a href="https://technet.microsoft.com/en-us/exdeploy2013/PrintChecklist?state=2718-W-FwAEAJCAVAgIAAEAAgAAABBRCQAA" rel="ugc">https://technet.microsoft.com/en-us/exdeploy2013/PrintChecklist?state=2718-W-FwAEAJCAVAgIAAEAAgAAABBRCQAA</a><br />
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Your exchange 2016 server can't automatically send emails to internet without configuration<br />
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After reboot have you checked all services on exchange server are running?
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Thank you for the link. I will go thru the info this morning. &nbsp;Let me give you a little information that I should have given before. The Exchange 2016 is trying to send thru the Exchange 2010. It recieves thru it. New and moved mailboxs can recieve from outside and inside they cannot send out from the 2016. The error message is coming back thru the inbox of the mailbix on the Exchange &nbsp;2016. It is trying to send thru the 2010. This is what we had wanted for now. Both are vm's.
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That is expected<br />
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Exchange 2016 will not automatically relay mails through Exchange 2010 to internet<br />
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U have to create send connector on Exchange 2016 for internet - use * as domain name<br />
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I assume that you have internet connectivity to Exchange 2016 or if at least smart host is configured where you can forward mails from ex 2016<br />
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<a href="https://technet.microsoft.com/en-us/library/jj657457(v=exchg.160).aspx" rel="ugc">https://technet.microsoft.com/en-us/library/jj657457(v=exchg.160).aspx</a>
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Yes, the Exchange 2016 did a great job of completing many task, it created the smarthost that the 2010 has. On the 2016 it shows the smarthost but it is still trying to connect to the 2010 to send out. I will work on the link you provided and lelt you know. Thank you for your help. In a coexistence environment can the 2010 send and receive for both exchange servers?<br />
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Below is the error.<br />
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Generating server: VMEXCHANGE<br />
&nbsp;Receiving server: SERVER1t (192.168.0.3)<br />
<br />
<br />
administrator@<br />
&nbsp;Remote Server at SERVER1t (192.168.0.3) returned '400 4.4.7 Message delayed'<br />
&nbsp;2/2/2016 12:56:03 AM - Remote Server at SERVER1 (192.168.0.3) returned '441 4.4.1 Error encountered while communicating with primary target IP address: &quot;421 4.4.2 Connection dropped due to ConnectionReset.&quot; Attempted failover to alternate host, but that did not succeed. Either there are no alternate hosts, or delivery failed to all alternate hosts. The last endpoint attempted was 192.168.0.3:25'
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I don't think it will create smart host automatically<br />
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I haven't work on 2016 yet,<br />
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can you create new internet send connector on 2016 and check if it resolve internet mails
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The send connector is was setup during the install of 2016. It shows the 2010 Exchange as being associated with the smarthost connector.<br />
<a href="https://filedb.experts-exchange.com/incoming/2016/02_w06/1079241/New-Rich-Text-Document--2-.rtf" target="_blank" class="file-inline" title="New-Rich-Text-Document--2-.rtf (4.6 MB)"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512"><path d="M67.508 468.467c-58.005-58.013-58.016-151.92 0-209.943l225.011-225.04c44.643-44.645 117.279-44.645 161.92 0 44.743 44.749 44.753 117.186 0 161.944l-189.465 189.49c-31.41 31.413-82.518 31.412-113.926.001-31.479-31.482-31.49-82.453 0-113.944L311.51 110.491c4.687-4.687 12.286-4.687 16.972 0l16.967 16.971c4.685 4.686 4.685 12.283 0 16.969L184.983 304.917c-12.724 12.724-12.73 33.328 0 46.058 12.696 12.697 33.356 12.699 46.054-.001l189.465-189.489c25.987-25.989 25.994-68.06.001-94.056-25.931-25.934-68.119-25.932-94.049 0l-225.01 225.039c-39.249 39.252-39.258 102.795-.001 142.057 39.285 39.29 102.885 39.287 142.162-.028A739446.174 739446.174 0 0 1 439.497 238.49c4.686-4.687 12.282-4.684 16.969.004l16.967 16.971c4.685 4.686 4.689 12.279.004 16.965a755654.128 755654.128 0 0 0-195.881 195.996c-58.034 58.092-152.004 58.093-210.048.041z"/></svg>New-Rich-Text-Document--2-.rtf</a>
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New-Rich-Text-Document--2-.rtf

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Add 2016 server on scoping tab<br />
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check what method is specified on &quot;Delivery&quot; tab<br />
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There you need to specify dns mx routing, if exch 2010 is listed there as smart host, you need to change it to dns routing
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Changing the settings to MX on the 2016 also changed the send connector on 2010. These servers are really connected. That stopped flow to the smarthost. At this point it almost looks like a network connection issue between the two servers. Again 2016 did 99 percent of the configuration in the coexistence &nbsp;with 2010, really amazing. The 2010 drops the connection. They are on Dell t430 host with broadcom cards. The mailboxes on 2016 can receive email from the internet and other mailboxes in the domain. I have 2 test mailboxes setup on the 2016 that can send to each other but not out. I migrated a user to 2016 and it could not send out or to the 2010 server mailboxes. I had to delete that mailbox and re-create it on the 2010 server for it to work again. I could not migrate her back to 2010 to get her working.
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Owa works and was configured during the installation. Autodiscover works connecting a Outlook client.
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on 2016 server, with internet based send connector If you remove 2010 from scoping tab and add 2016 there you should be able to send mails out to internet
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Yes, I was able to send to a gmail account
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If you haven't face any errors during installation, you could do below<br />
make sure both 2010 and 2016 can communicate with each other<br />
UR mail flow should work between both servers internally<br />
change MX to 2016<br />
you already added send connector<br />
Point autodiscover record to 2016 server
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Okay, I have it back to using the smart host. I had to add the 2016 server as a source server in order for it to send directly to the internet. I switched it back to smarthost and restarted the transport services on the 2016 and now all &nbsp;emails are going out to the internet. So in the send connector it only had the 2010 server, by adding the 2016 it now is sending to the internet with the smarthost but, always a but, I still cannot send to mailboxes on the 2010 server. I should start another question? <br />
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Thank you Mahesh
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<div class="content wysiwyg-content">
I have a Exchange 2010 with mailboxes that still have the First Administrators Group Legacy attributes. I have installed Exchange 2016 on a new server all looks well. If I create a mailbox in Exchange 2016 or migrate a mailbox from 2010 to 2016 no mail can be sent to mailboxes outside the domain or on the Exchange 2010 server. I get an error back<br />
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421 4.4.2 connection dropped due to socketerror <br />
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The Exchange 2016 server cannot connect to the Exchange 2010
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I have a Exchange 2010 with mailboxes that still have the First Administrators Group Legacy attributes. I have installed Exchange 2016 on a new server all looks well. If I create a mailbox in Exchange 2016 or migrate a mailbox from 2010 to 2016 no mail can be sent to mailboxes outside the domain or on the Exchange 2010 server. I get an error back

421 4.4.2 connection dropped due to socketerror 

The Exchange 2016 server cannot connect to the Exchange 2010

Exchange 2010 Coexist with Exchange 2016

Exchange is the server side of a collaborative application product that is part of the Microsoft Server infrastructure. Exchange's major features include email, calendaring, contacts and tasks, support for mobile and web-based access to information, and support for data storage.

Exchange

Within Internet message handling services (MHS), a message transfer agent or mail transfer agent (MTA) or mail relay is software that transfers electronic mail messages from one computer to another using a client–server application architecture. A MTA implements both the client (sending) and server (receiving) portions of the Simple Mail Transfer Protocol (SMTP). The terms mail server, mail exchanger, and MX host may also refer to a computer performing the MTA function. The Domain Name System (DNS) associates a mail server to a domain with mail exchanger (MX) resource records containing the domain name of a host providing MTA services.