Which program/task is using port .. on Windows

Today I ran into the issue that the SMTP server of my beloved Domino server was not able to startup due to the following error message after a reboot of the Windows server:

06.03.2020 08:02:38 SMTP Server: Another application is already listening on port 25: 220 NOTES02 SMTP Server ready
06.03.2020 08:02:38 SMTP Server: Started
06.03.2020 08:02:38 SMTP Server: Listener failure, TCP/IP port number [25] is already in use on this system
06.03.2020 08:02:38 Suspending listen task for 20 seconds due to network errors

So what was causing the SMTP to startup ? To find out just enter the following command in a command prompt window:

netstat -aon | findstr 25

Then you will get all services listening to port *25*


With this information you just have to search for PID “8” in the Task Manager and either kill the task or end the service.


There´s also another way I received from Harald Reisinger:

With Powershell: Get-NetTCPConnection -LocalPort 25 | Select-Object -Property @{ Name=’Id’; Expression={$_.OwningProcess}} | Get-Process

Thanks to Harald for sharing this great information !

Domino V10+ error message: ‘DB in use by another process’

On multiple customer environments running Domino on Windows Server 2016 you always receive the mentioned error when trying to delete a database.

One customer also had issues by accessing the FT index of databases after the Domino V10 migration.

First I thought that running the Domino servers in a clustered environment caused this issue but it´s much more easier:

Just exclude the Domino Data directory from being scanned by the Windows Defender. Afterwards everything´s running fine and you also are able to delete databases.

Right now I received the information from Uli that there´s a known bug in 10.0.1+ where DAOSMgr is not releasing database handles after running a “resync” or a “resync force”. But there´s a HotFix for 10.0.1 FP1 with SPR # GFALBCFAK3. So it seems that this fix is not included in 10.0.1 FP2 ( fix list ) because the fix was released just the day before FP2.