What is this - I have asked the server to move a public folder mailbox from 16>19 Exchange Server and see these two, but they appear related to mail flow???

Log Name: Application
Source: MSExchangeApplicationLogic
Date: 31/01/2021 15:33:43
Event ID: 3018
Task Category: Extension
Level: Error
Keywords: Classic
User: N/A
Computer: server.domain.local
Description:
https://api.addins.omex.office.net/appinfo/query?rt=XML&corr=589e2fb3-be9f-4279-ae60-a3ceb85fb0d3  Exception: System.Net.WebException: The underlying connection was closed: An unexpected error occurred on a send. ---> System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host
at System.Net.Sockets.Socket.EndReceive(IAsyncResult asyncResult)
at System.Net.Sockets.NetworkStream.EndRead(IAsyncResult asyncResult)
--- End of inner exception stack trace ---
at System.Net.TlsStream.EndWrite(IAsyncResult asyncResult)
at System.Net.ConnectStream.WriteHeadersCallback(IAsyncResult ar)
--- End of inner exception stack trace ---
at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
at Microsoft.Exchange.Data.ApplicationLogic.Extension.BaseAsyncOmexCommand.<>c__DisplayClass2.b__1()
Event Xml:



3018
2
3
0x80000000000000

18701952
Application
server.domain.local



GetKillBit
589e2fb3-be9f-4279-ae60-a3ceb85fb0d3


https://api.addins.omex.office.net/appinfo/query?rt=XML&corr=589e2fb3-be9f-4279-ae60-a3ceb85fb0d3
System.Net.WebException: The underlying connection was closed: An unexpected error occurred on a send. ---> System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host
at System.Net.Sockets.Socket.EndReceive(IAsyncResult asyncResult)
at System.Net.Sockets.NetworkStream.EndRead(IAsyncResult asyncResult)
--- End of inner exception stack trace ---
at System.Net.TlsStream.EndWrite(IAsyncResult asyncResult)
at System.Net.ConnectStream.WriteHeadersCallback(IAsyncResult ar)
--- End of inner exception stack trace ---
at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
at Microsoft.Exchange.Data.ApplicationLogic.Extension.BaseAsyncOmexCommand.<>c__DisplayClass2.<EndGetResponseCallback>b__1()




Log Name: Application
Source: MSExchangeApplicationLogic
Date: 31/01/2021 15:33:43
Event ID: 3025
Task Category: Extension
Level: Error
Keywords: Classic
User: N/A
Computer: server.domain.local
Description:
Scenario: GetKillBit. Failed to download killbit list from OMEX server. Exception: System.Net.WebException: The underlying connection was closed: An unexpected error occurred on a send. ---> System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host
at System.Net.Sockets.Socket.EndReceive(IAsyncResult asyncResult)
at System.Net.Sockets.NetworkStream.EndRead(IAsyncResult asyncResult)
--- End of inner exception stack trace ---
at System.Net.TlsStream.EndWrite(IAsyncResult asyncResult)
at System.Net.ConnectStream.WriteHeadersCallback(IAsyncResult ar)
--- End of inner exception stack trace ---
at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
at Microsoft.Exchange.Data.ApplicationLogic.Extension.BaseAsyncOmexCommand.<>c__DisplayClass2.b__1()
Event Xml:



3025
2
3
0x80000000000000

18701953
Application
server.domain.local



GetKillBit
System.Net.WebException: The underlying connection was closed: An unexpected error occurred on a send. ---> System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host
at System.Net.Sockets.Socket.EndReceive(IAsyncResult asyncResult)
at System.Net.Sockets.NetworkStream.EndRead(IAsyncResult asyncResult)
--- End of inner exception stack trace ---
at System.Net.TlsStream.EndWrite(IAsyncResult asyncResult)
at System.Net.ConnectStream.WriteHeadersCallback(IAsyncResult ar)
--- End of inner exception stack trace ---
at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
at Microsoft.Exchange.Data.ApplicationLogic.Extension.BaseAsyncOmexCommand.<>c__DisplayClass2.<EndGetResponseCallback>b__1()