On-premise are not receiving email

[Yousuf Khan]

We are running Hybird environment and since few days on-premise users are not receiving email or would receive late like after hour or so.

I sent one email from office 365 user to on-premise user and run a message trace and found status pending and below error:

Original FQDN and Traget IP is removed from the below error.

Reason: [{LED=451 4.7.0 Temporary server error. Please try again later. PRX5 };{MSG=};{FQDN=abc.ca};{IP=0.0.0.0};{LRT=2/29/2020 4:13:41 AM}]. OutboundProxyTargetIP: 0.0.0.0. OutboundProxyTargetHostName: abc.ca

Any suggestions? thank you in advance!

[#2]

how did you setup your environment, did you setup using HCW ? are there any firewall, are the ports open?

[#3]

@Adnan Rafique 

Yes we did setup through HCW.

When messages sent it shows pending in message trace and give the below

It would be send if failed then would get a below error: original domain name has been replaced with abc.

Reason: [{LED=554 5.4.14 Hop count exceeded - possible mail loop ATTR34 [QB1CAN01FT015.eop-CAN01.prod.protection.outlook.com]};{MSG=};{FQDN=abc-ca.mail.protection.outlook.com};{IP=104.47.60.36};{LRT=2/29/2020 5:16:28 AM}]. OutboundProxyTargetIP: 104.47.60.36. OutboundProxyTargetHostName: abc-ca.mail.protection.outlook.com

In O365 outbound connector i have included on-premise exchange FQDN and our default domain.

Should we removed default domain?

Thanks,

[#4]

Hello Yousuf khan,
I hope you validated the connector successfully. Just issue might be with Looping the mail from o365 to On-premises. Check with your Default Accepted Domain and keep domain type as Relay. Hope this will solve your problem.