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Hi, I have migrated my exchange 2016 Org to 2019. Before I decommissioned 2016 I ran the exchange hybrid wizard and selected the exchange 2019 servers. I only have a handful of mailboxes in O365 but when they mail to on-premise I get the following error. returned '450 4.4.316 Connection refused [Message=Socket error code 10061] Any help would be great. Thanks
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@onthejob Just wanted to check if the answer shared below helped. If it helped, then would request you to please "Accept the answer" as it would be helpful to others in the community as well.
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Hello @onthejob
I did some research. I found that this error seems to be related to port 25. Please try to unlock port 25. A10061 error is caused by either a firewall or anti-virus software presence on the local computer or network connection. please check this thread Sort by time Homer Sibayan's two answers.
Regards
SF
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