I tried this last week and below is the automated response:
Thank you for contacting Immigration, Refugees and Citizenship Canada (IRCC). Please note that this is an automated message.
This mailbox should
ONLY be used to provide documentation related to an online test or to provide a reasonable explanation for missing or being unable to attend an online test (with documentary evidence). To facilitate the processing of your request, you must include your full name, file number and UCI.
Take note that any requests received other than for an online test or for a justification of absence, will be automatically deleted and not processed.
Please note that there is no need to schedule an appointment to take the online test as long as your invitation is active.
If you are experiencing technical issues before accessing the online test, please contact
IRCC.CitOnlineTest-TestenligneCit.IRCC@cic.gc.ca as well.
For any specific inquiries regarding your application, we invite you to complete the
IRCC Web form.
Thank you,