I noticed that every day in the IIS log there are strange errors related to OWA:

[2020.05.20] [CurrentUser: SYSTEM] [2020.05.20] [20/05/2020 11:48:35] [2020.05.20] https://mail3.sersis.com/owa/auth/logon.aspx?replaceCurrent=1&url=http:%2F%2Fowa.mail3.sersis.com%2Fowa%2F [2020.05.20] Application Error. Message: The file '/owa/auth/logon.aspx' does not exist., Stack Trace:    at System.Web.UI.Util.CheckVirtualFileExists(VirtualPath virtualPath) [2020.05.20]    at System.Web.Compilation.BuildManager.GetVPathBuildResultInternal(VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile, Boolean throwIfNotFound, Boolean ensureIsUpToDate) [2020.05.20]    at System.Web.Compilation.BuildManager.GetVPathBuildResultWithNoAssert(HttpContext context, VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile, Boolean throwIfNotFound, Boolean ensureIsUpToDate) [2020.05.20]    at System.Web.Compilation.BuildManager.GetVirtualPathObjectFactory(VirtualPath virtualPath, HttpContext context, Boolean allowCrossApp, Boolean throwIfNotFound) [2020.05.20]    at System.Web.Compilation.BuildManager.CreateInstanceFromVirtualPath(VirtualPath virtualPath, Type requiredBaseType, HttpContext context, Boolean allowCrossApp) [2020.05.20]    at System.Web.UI.PageHandlerFactory.GetHandlerHelper(HttpContext context, String requestType, VirtualPath virtualPath, String physicalPath) [2020.05.20]    at System.Web.HttpApplication.MaterializeHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() [2020.05.20]    at System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step) [2020.05.20]    at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

Also today I noticed some other strange errors related to no longer realted to OWA:

[2020.05.20] [CurrentUser: SYSTEM] [2020.05.20] [20/05/2020 11:52:16] [2020.05.20] https://mail3.sersis.com/https:/mail3.sersis.com/ [2020.05.20] Application Error. Message: Valore potenzialmente pericoloso Request.Path rilevato dal client (:)., Stack Trace:    in System.Web.HttpRequest.ValidateInputIfRequiredByConfig() [2020.05.20]    in System.Web.HttpApplication.PipelineStepManager.ValidateHelper(HttpContext context) [2020.05.20] ======= [2020.05.20] [CurrentUser: SYSTEM] [2020.05.20] [20/05/2020 11:52:16] [2020.05.20] https://mail3.sersis.com/https:/mail3.sersis.com/ [2020.05.20] Application Error. Message: Valore potenzialmente pericoloso Request.Path rilevato dal client (:)., Stack Trace:    in System.Web.HttpRequest.ValidateInputIfRequiredByConfig() [2020.05.20]    in System.Web.HttpApplication.PipelineStepManager.ValidateHelper(HttpContext context)

Since I don't know what they depend on I attach the logs of some days and I ask you if you can enlighten me on the meaning.

Thanks in advance