eM Client cannot open SSL/TLS link to Owncloud server (self-signed certs)

I’m currently evaluating the latest version of eM Client.

I’m trying to open an SSL/TLS connection from eM Client (under Windows 10 Pro) to a self-hosted Owncloud CalDAV/CardDAV server (under Debian wheezy and Apache 2.2) in order to synchronize several address books and calendars on multiple accounts. The server is configured to use self-signed certificates. The self-signed certificates were installed in the certificate store of the client machine (Windows 10 Pro).

I’m able to connect successfully to the Owncloud server using SSL 1) from my iPad iOS 9.1 (and sync both contacts and calendars), 2) from Outlook 2007, using the open source Outlook CalDAV synchronizer connector, and 3) from Android 4.1 using the CardDAV-Sync free and CalDAV-Sync apps.

Unfortunately, no matter which URL I’m trying to use, I was not able to connect once with eM Client to the Owncloud server. Error messages indicate that the SSL/TLS connection could not be opened.

Ignoring the fact that the server is running self-signed certs, the ssllabs otherwise rates my site with an ‘A’ grade.

How to solve this issue?

Thanks.

Hi Pete,
could you please tell me which version of eM Client are you running and possibly screenshot the error popup for me, so I can get a better idea what the problem looks like?

Best regards,
Olivia

Hi Olivia,

On the client side, I’m running eM Client, version 6.0.23421.0 on Windows 10 Pro 64-bit.

On the server side, I’m running ownCloud 8.1.3 (with the Calendar 0.7.3 and Contacts 0.4.0.1 apps enabled), Debian Wheezy, Apache 2.2.22.

Here are the steps to reproduce:

  1. Start eM Client.

  2. Go to menu Tools > Accounts.

  3. In the dialog box ‘New Account’, expand ‘Calendar’ and select ‘CalDAV’.

  4. Server information:

step 1:

Account address URL: (I copied the CalDAV link URL generated by Owncloud for a specific calendar)
https:// domain>/owncloud/remote.php/caldav/calendars//

User name:


Password:



step 2:

Account name:



step 3:

Press 'Finish’

5) At this point the error window opens:

----- begin log -----
00:55:04 pierre [CalDAV / CardDAV] MailExceptions.ConnectionException: The request was aborted: Could not create SSL/TLS secure channel. —> System.Net.WebException: The request was aborted: Could not create SSL/TLS secure channel.
00:55:04 at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
00:55:04 at MailClient.CalDav.ProtocolCommands.RequestCommand.Execute(HttpWebRequest httpRequest, CancellationToken cancellationToken, Action`1 logBody)
00:55:04 at MailClient.CalDav.ProtocolCommands.Connector.RunCommand(CalDavAccount account, ICommand command, CancellationToken cancellationToken)
00:55:04 — End of inner exception stack trace —
00:55:04 at MailClient.CalDav.ProtocolCommands.Connector.RunCommand(CalDavAccount account, ICommand command, CancellationToken cancellationToken)
00:55:04 at MailClient.CalDav.Synchronizer.BootstrapCommand.UpdateOptions(Uri[] baseUris)
00:55:04 at MailClient.CalDav.Synchronizer.BootstrapCommand.Execute(WorkerStatus status)
00:55:04 at MailClient.Commands.Command.Process(WorkerStatus status)
----- end log -----

Best Regards,

Pierre

Hi Pete,
may I ask what antivirus program do you use? Or do you only use windows firewall? I think it could be blocking the creation of the channel.

Hi Olivia,

I’m using Bitdefender (current version of engine and virus definitions) as my firewall.

Disabling the firewall doesn’t seem to make a difference (same error generated by eM Client).

note: I have only 5 days left for my evaluation period of eM Client.

Best regards,

Pierre

Hello Pierre,
could you please try uninstalling the current version and running this one > http://www.emclient.com/dist/v6.0.231… and see if the same problem occurs?

Best regards,
Olivia

Hello Olivia,

Just uninstalled version 6.0.23421.0, downloaded and installed version 6.0.23181.0, and started eM Client, but unfortunately, I get the same error :frowning:

Best regards,

Pierre

Hi Pierre,
can you try, while running the 6.0.23181.0 version, turn off bitdefender completely for a while and see if the issue persists?

Best regards,
Olivia