Here are the logs from the client. I think it has to do with outlook.com changing, but not sure
10:16:51 AM [email protected] [AirSync] Synchronizing folder list10:16:53 AM [email protected] [AirSync] Synchronizing folder list10:16:54 AM [email protected] [AirSync] Synchronizing folder ‘[email protected]/Outbox/’
10:16:54 AM [email protected] [AirSync] MailExceptions.ConnectionException: Found invalid data while decoding. —> System.IO.InvalidDataException: Found invalid data while decoding.
10:16:54 AM at MailClient.Protocols.AirSync.AirSyncItemSynchronizer2.GetSyncKey(Folder folder, IItemContext context, CancellationToken cancellationToken) 10:16:54 AM at MailClient.Protocols.AirSync.AirSyncItemSynchronizer2.Synchronize(IItemSynchronizeContext1 synchronizeContext, Folder folder, CancellationToken cancellationToken) 10:16:54 AM at MailClient.Protocols.Common.ItemSynchronizer2.<>c__DisplayClass2e.<>c__DisplayClass33.b__2a(WorkerStatus status, CancellationToken cancellationToken)
10:16:54 AM at MailClient.Protocols.AirSync.AirSyncGenericCommand.Execute(WorkerStatus status)
10:16:54 AM — End of inner exception stack trace —