Outlook 2013 Unknown error 0x800xxx69

I have an IMAP account that works correctly on other e-mail clients, but in Outlook when testing the account setup, it fails with the message: Unknown error 0x800xxx69.

I tried the solutions proposed in the following links, but with none of the options I could make the sending of emails work.

• https://support.microsoft.com/es-es/help/813514/error-occurs-when-you-send-or-receive-an-email-message-in-outlook-or-outlook-express
• https://answers.microsoft.com/en-us/msoffice/forum/msoffice_outlook-mso_other/sending-error-with-outlook-2010/bc29ee46-81e9-455b-93b3-8588cd71d100

I am using Microsoft Outlook 2013 (15.0.4893.1000) on Windows 10 64bit.

Account type: IMAP
Incoming Server Port: 993
Outgoing Server Port: 465
Authentication is required: True