Considering sysmail_event_log
the description is as follows
DatabaseMail process is started
1) Exception Information =================== Exception Type: System.NullReferenceException Message: Object reference not set to an instance of an object. Data: System.Collections.ListDictionaryInternal TargetSite: Microsoft.SqlServer.Management.SqlIMail.Server.Objects.Account GetAccount(Int32) HelpLink: NULL Source: DatabaseMailEngine StackTrace Information =================== at Microsoft.SqlServer.Management.SqlIMail.Server.DataAccess.DataAccessAdapter.GetAccount(Int32 accountID) at Microsoft.SqlServer.Management.SqlIMail.Server.DataAccess.SessionManager.GetAccount(Int32 accountID) at Microsoft.SqlServer.Management.SqlIMail.Server.Controller.CommandFactory.CreateSendMailCommand(DBSession dbSession) at Microsoft.SqlServer.Management.SqlIMail.Server.Controller.CommandFactory.CreateCommand(DBSession dbSession) at Microsoft.SqlServer.Management.SqlIMail.Server.Controller.CommandRunner.Run(DBSession db) at Microsoft.SqlServer.Management.SqlIMail.IMailProcess.ThreadCallBack.MailOperation(Object o)
1) Exception Information =================== Exception Type: System.NullReferenceException Message: Object reference not set to an instance of an object. Data: System.Collections.ListDictionaryInternal TargetSite: Microsoft.SqlServer.Management.SqlIMail.Server.Objects.Account GetAccount(Int32) HelpLink: NULL Source: DatabaseMailEngine StackTrace Information =================== at Microsoft.SqlServer.Management.SqlIMail.Server.DataAccess.DataAccessAdapter.GetAccount(Int32 accountID) at Microsoft.SqlServer.Management.SqlIMail.Server.DataAccess.SessionManager.GetAccount(Int32 accountID) at Microsoft.SqlServer.Management.SqlIMail.Server.Controller.CommandFactory.CreateSendMailCommand(DBSession dbSession) at Microsoft.SqlServer.Management.SqlIMail.Server.Controller.CommandFactory.CreateCommand(DBSession dbSession) at Microsoft.SqlServer.Management.SqlIMail.Server.Controller.CommandRunner.Run(DBSession db) at Microsoft.SqlServer.Management.SqlIMail.IMailProcess.ThreadCallBack.MailOperation(Object o)
1) Exception Information =================== Exception Type: System.NullReferenceException Message: Object reference not set to an instance of an object. Data: System.Collections.ListDictionaryInternal TargetSite: Microsoft.SqlServer.Management.SqlIMail.Server.Objects.Account GetAccount(Int32) HelpLink: NULL Source: DatabaseMailEngine StackTrace Information =================== at Microsoft.SqlServer.Management.SqlIMail.Server.DataAccess.DataAccessAdapter.GetAccount(Int32 accountID) at Microsoft.SqlServer.Management.SqlIMail.Server.DataAccess.SessionManager.GetAccount(Int32 accountID) at Microsoft.SqlServer.Management.SqlIMail.Server.Controller.CommandFactory.CreateSendMailCommand(DBSession dbSession) at Microsoft.SqlServer.Management.SqlIMail.Server.Controller.CommandFactory.CreateCommand(DBSession dbSession) at Microsoft.SqlServer.Management.SqlIMail.Server.Controller.CommandRunner.Run(DBSession db) at Microsoft.SqlServer.Management.SqlIMail.IMailProcess.ThreadCallBack.MailOperation(Object o)
1) Exception Information =================== Exception Type: System.NullReferenceException Message: Object reference not set to an instance of an object. Data: System.Collections.ListDictionaryInternal TargetSite: Microsoft.SqlServer.Management.SqlIMail.Server.Objects.Account GetAccount(Int32) HelpLink: NULL Source: DatabaseMailEngine StackTrace Information =================== at Microsoft.SqlServer.Management.SqlIMail.Server.DataAccess.DataAccessAdapter.GetAccount(Int32 accountID) at Microsoft.SqlServer.Management.SqlIMail.Server.DataAccess.SessionManager.GetAccount(Int32 accountID) at Microsoft.SqlServer.Management.SqlIMail.Server.Controller.CommandFactory.CreateSendMailCommand(DBSession dbSession) at Microsoft.SqlServer.Management.SqlIMail.Server.Controller.CommandFactory.CreateCommand(DBSession dbSession) at Microsoft.SqlServer.Management.SqlIMail.Server.Controller.CommandRunner.Run(DBSession db) at Microsoft.SqlServer.Management.SqlIMail.IMailProcess.ThreadCallBack.MailOperation(Object o)
DatabaseMail process is shutting down