Unable to send or receive messages with imap-mail.outlook.com, error 0x800CCC0F

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Unable to send or receive messages for the Hotmail (1) account. Some of the messages in your Outbox Folder could not be copied to your Sent Items Folder. Your message could not be uploaded to the IMAP server. The server refused to accept it.

Subject 'Fw: '
Server Response: This IMAP command could not be sent to the server before the connection was terminated.
Server: 'imap-mail.outlook.com'
Windows Live Mail Error ID: 0x800CCC0F
Protocol: IMAP
Port: 993
Secure(SSL): Yes

This account will often not send or receive messages, or if they receive them I cannot open them.  Can anyone help please?