Can't send email from new Exchange 2016 server

Question

Hi everyone,

I'm experiencing a curious situation with a client context.
I'm working on the migration from an Exchange 2010 to 2016.

The new server is up, dns is up to date, smtp, owa is pointing to the new exchange server.
Firewall rules are ok and there is no local antivirus or firewall installed on the windows exchange server.

For the moment there is no migrated client mailbox to 2016, I'm just testing with test mailboxes created/migrated to 2016.

Problem is that I can't send emails from mailboxes located to this new exchange server.
Emails are stucked in drafts (owa) or sent but never received (outlook)..
Receive is ok but sending is ko.

The send connector is including also the new exchange server.
All the arbitration mailboxes have been migrated to the new exchange database, so I don't know what is wrong...

I've checked with the test-mailflow and received a failure result like this :

RunspaceId : 04bfdc9a-f3f7-42e3-90f8-6b3ab99d2955
TestMailflowResult : FAILURE
MessageLatencyTime : 00:00:00
IsRemoteTest : False
Identity :
IsValid : True
ObjectState : New

RunspaceId : 04bfdc9a-f3f7-42e3-90f8-6b3ab99d2955
Events : {Source : MSExchange Monitoring Mailflow Local
ID : 1001
Type : Error
Message : L'accusé de réception pour le message test de VMEXCHANGE16\SystemMailbox{9baa1ad3-4358-489d-be63-5f075ca657d9}@exserver.ch à
VMEXCHANGE16\SystemMailbox{9baa1ad3-4358-489d-be63-5f075ca657d9}@exserver.ch n'a pas été reçu dans le délai de latence d'erreur de 1 secondes. La cmdlet n'attendra plus
l'accusé de réception.}
PerformanceCounters : {Objet : MSExchange Monitoring Mailflow Local
Compteur : Mailflow Latency
Instance : VMEXCHANGE16\EX16DB1
Valeur : -1}

Any idea of what is goin on ?

Thank you,

Answer 1

The last event is suspicious. It indicates an issue with transport services. Check, if the ports are assigned correctly in all the receive connectors.
The ports are as follows:

Client Proxy: 465
Client Frontend: 587
Default: 2525
Default Frontend: 25
Outbound Proxy Frontend:717
After assigning the correct port, restart transport services to see if the issue is solved. Sometimes, you may need to recreate the connector (in case, the settings were corrupted before)

Port reference here: receive-connectors

Answer 2

Thank you for your reply !
In first I was thinking "why talking receive connector when my problem is sending emails...".
Then I've decided to check what you said and indeed the Outbound Proxy Frontend connector was removed (I've attempted first to reproduce the exchange 2010 connectors... fatal error).
So the problem was that a mendatory connector builtin 2016 was removed, thinking that it was not needed with the 2010.

Well thank you so much, everything is fine now !