Email error

Hi,
Im randomly getting an error with an email flow that started last week (around the time our licence expired and had to be renewed). Im checking for headers every 5 minutes and a few times each hour I get an error logging into imap server. I have captured the full trace as below. Should I turn on Secure Connection for all of my email steps? Im a bit unsure what happened here as I was running error free up until last Thursday. Regards, Shaun -----Original Message----- From: decisions@riotinto.com [mailto:decisions@riotinto.com] Sent: Wednesday, 29 November 2017 10:54 PM To: Centa, Shaun (G&I) Subject: email error DecisionsFramework.Design.Flow.ErrorRunningFlowStep: Error running step Get Headers 1[GetHeaders] in flow [Decisions email handler]: error logging into imap server as user sa-decisions@riotinto.com ---> System.Exception: error logging into imap server as user sa-decisions@riotinto.com ---> Rebex.Net.ImapException: None of the supported authentication methods is accepted by the server. Try using TLS/SSL connection. at Rebex.Net.Imap.Login(String userName, String password, ImapAuthentication method) at DecisionsFramework.Design.Flow.CoreSteps.EMail.Imap.BaseImapStep.Login(StepStartData data) --- End of inner exception stack trace --- at DecisionsFramework.Design.Flow.CoreSteps.EMail.Imap.BaseImapStep.Login(StepStartData data) at DecisionsFramework.Design.Flow.CoreSteps.EMail.Imap.BaseImapStep.Run(StepStartData data) at DecisionsFramework.Design.Flow.FlowStep.RunStepInternal(String flowTrackingID, String stepTrackingID, KeyValuePairDataStructure[] stepRunDataValues, AbstractFlowTrackingData trackingData) at DecisionsFramework.Design.Flow.FlowStep.Start(String flowTrackingID, String stepTrackingID, FlowStateData data, AbstractFlowTrackingData trackingData, RunningStepData currentStepData) --- End of inner exception stack trace ---?????