emClient won’t sync CalDAV and CardDAV over SSL encrypted URL

I use Tine 2.0 ( on my Synology NAS with an officially signed SSL certificate. All clients work fine when synchronizing CalDAV or CardDAV over SSL (e.g. DAVDroid, Mac OS X, iOS etc.).

Only em Client seems to be unable to establish a connection when I enter a https:// URL for CardDAV or CalDAV. I can finish the setup dialogue, but my calenders or respectively contacts won’t appear, but I get an error message telling me that the connection was closed (or something like that).

When I use a non-SSL URL, the synchronization process works just fine. The calendars arrive as well as my contacts, I can edit them, add some etc.

What can I do to make SSL work with em Client. The Beta 7 won’t work either - same issue.


https:// URL for CalDAV and CardDAV should work with eM Client (both 6 and 7). There must be something with your server setting.
Could you copy the Error message and the log from Tools>Operations window when you try to connect to your server?


Hello Olivia,
em Client is the only client which is not able to synchronize CalDAV and CardDAV data over SSL. The non-SSL URL works fine in em Client, the SSL URL works fine with all other clients - even Thunderbird, which I tried today. So I guess it has nothing to do with my server settings, especially since there are more people on the forum here who have SSL problems as well.

Here what I copied:

18:40:18   MailExceptions.Exception: Während der Synchronisation des CalDAV-Ordners ist ein Fehler aufgetreten:System.InvalidOperationException: Der Vorgang ist aufgrund des aktuellen Zustands des Objekts ungültig.
18:40:18    bei System.Linq.Enumerable.Futures1.<.cctor>b__da()<br>18:40:18 bei System.Linq.Enumerable.FirstImpl[TSource](IEnumerable1 source, Func1 empty)<br>18:40:18 bei System.Linq.Enumerable.First[TSource](IEnumerable1 source)
18:40:18 bei MailClient.TimeZone.TimeZoneConvert.FromiCalendar(TimeZone timeZone)
18:40:18 bei MailClient.Schedule.ScheduleConvert.UpdateScheduleObjectFromComponent(IScheduleObject scheduleObject, Calendar calendar, ScheduleComponent updatingComponent, ScheduleConvertOptions options)
18:40:18 bei MailClient.Schedule.Event.EventComposer…ctor(Calendar calendarObject, Event clonedComponent, IEvent parentItem, Boolean removeMethod)
18:40:18 bei MailClient.CalDav.Synchronizer.EventItemSynchronizer.CreateItem(Folder folder, Component payloadComponent, Uri uri, String eTag, CancellationToken cancellationToken)
18:40:18 bei MailClient.CalDav.Synchronizer.SynchronizeItemsCommand.CreateCalDavItem(Stream payloadStream, Encoding encoding, Uri uri, String eTag)
18:40:18 bei MailClient.CalDav.Synchronizer.SynchronizeItemsCommand.CreateCalDavItem(ResponseItem item)
18:40:18 bei MailClient.CalDav.Synchronizer.SynchronizeItemsCommand.DownloadItemsMultiget(IList1 uris, Boolean calDav)<br>18:40:18 bei MailClient.CalDav.Synchronizer.SynchronizeItemsCommand.DownloadCalDavItems(IList1 uris)
18:40:18 bei MailClient.CalDav.Synchronizer.SynchronizeItemsCommand.ProcessItems(Dictionary2 items, Boolean deltaSyncReport)<br>18:40:18 bei MailClient.CalDav.Synchronizer.SynchronizeItemsCommand.Execute(WorkerStatus status)<br>18:40:18 bei MailClient.CalDav.Synchronizer.SynchronizeItemsCommand.Execute(WorkerStatus status)<br>18:40:18 bei MailClient.Commands.Command.Process(WorkerStatus status)<br>18:41:57 Termine [CalDAV / CardDAV] MailExceptions.ConnectionException: Die zugrunde liegende Verbindung wurde geschlossen: Unerwarteter Fehler beim Senden.. ---&gt; System.Net.WebException: Die zugrunde liegende Verbindung wurde geschlossen: Unerwarteter Fehler beim Senden.. ---&gt; System.IO.IOException: Von der Übertragungsverbindung können keine Daten gelesen werden: Eine vorhandene Verbindung wurde vom Remotehost geschlossen. ---&gt; System.Net.Sockets.SocketException: Eine vorhandene Verbindung wurde vom Remotehost geschlossen<br>18:41:57 bei System.Net.Sockets.Socket.EndReceive(IAsyncResult asyncResult)<br>18:41:57 bei System.Net.Sockets.NetworkStream.EndRead(IAsyncResult asyncResult)<br>18:41:57 --- Ende der internen Ausnahmestapelüberwachung ---<br>18:41:57 bei System.Net.TlsStream.EndWrite(IAsyncResult asyncResult)<br>18:41:57 bei System.Net.PooledStream.EndWrite(IAsyncResult asyncResult)<br>18:41:57 bei System.Net.ConnectStream.WriteHeadersCallback(IAsyncResult ar)<br>18:41:57 --- Ende der internen Ausnahmestapelüberwachung ---<br>18:41:57 bei System.Net.HttpWebRequest.EndGetRequestStream(IAsyncResult asyncResult, TransportContext&amp; context)<br>18:41:57 bei System.Net.HttpWebRequest.EndGetRequestStream(IAsyncResult asyncResult)<br>18:41:57 bei MailClient.CalDav.ProtocolCommands.RequestCommand.Execute(HttpWebRequest httpRequest, CancellationToken cancellationToken, Action1 logBody)
18:41:57 bei MailClient.CalDav.ProtocolCommands.Connector.RunCommand(CalDavAccount account, ICommand command, CancellationToken cancellationToken)
18:41:57 — Ende der internen Ausnahmestapelüberwachung —
18:41:57 bei MailClient.CalDav.ProtocolCommands.Connector.RunCommand(CalDavAccount account, ICommand command, CancellationToken cancellationToken)
18:41:57 bei MailClient.CalDav.Synchronizer.BootstrapCommand.UpdateOptions(Uri[] baseUris)
18:41:57 bei MailClient.CalDav.Synchronizer.BootstrapCommand.Execute(WorkerStatus status)
18:41:57 bei MailClient.Commands.Command.Process(WorkerStatus status)</.cctor>

So? Nothing?
I guess I just stay with Thunderbird - it works at least even if it is not as beautifully designed as emClient.

I’m sorry for the lack of reply, I didn’t hear from our team regarding this issue.
Have you tried to see if the BETA update fixes this issue?
If not, we can set up more detailed CalDAV logging and analyze those.


Well, is there a new Beta 7 Version? The last one I tried last week did not work either - exact same problem.