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Exchange popProxy

channaveera Swamy KM 6 Reputation points
2022-02-02T04:45:05.5+00:00

Hi All,

We had noticed an issue with POP3 proxying. We initially had 3 exchange serves and they proxied pop3 connections among them selves to port ProxyTargetPort : 9955

We recently introduced 2 more exchange servers all the 5 exchange serves are configured with ProxyTargetPort : 9955. The 2 new exchange servers proxy the POP3 connections to old servers on port 9955 but when the older 3 server try to proxy the POP3 connections to 2 new exchange servers they try to connect it on port 1995 and the connection refused.

All 4 servers are in the same AD site.

PO3 proxy from New server to old servers
R=ok;Msg="Proxy:Old-server:9955:SSL;ProxySuccess";ActivityContextData=4a1218cc-4277-47f9-b97a-2f96bc87fbc5

PO3 proxy from old servers to New servers
R="-ERR Logon failure: unknown user name or bad password.";Msg=Proxy:New-Server:1995:SSL;ErrMsg=ProxyFailed;Excpt="A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond New-Server:1995-System.Net.Sockets.SocketException";

Exchange Server Management
Exchange Server Management
Exchange Server: A family of Microsoft client/server messaging and collaboration software.Management: The act or process of organizing, handling, directing or controlling something.
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  1. channaveera Swamy KM 6 Reputation points
    2022-02-02T09:44:22.62+00:00

    What are the CU versions of the old and new Exchange servers? - E2013 CU23 build number 15.0.1497.28

    All exchange servers are configured with ProxyTargetPort set to 9955. We didn't make any changes to default config of POP3. it was already set to 9955. I got it changes to 1995 on the new serves but there is no TCP /UDP port listening on exchange servers on this port. I did a telnet from old server to new serves on port 1995. There is no response though the ports 9955, 1995 both are enabled on windows filewall on both old and new serves.