Issue Summary

Starting in Confluence 9.0+, when an end user receives a mail notification regarding Calendar events, and they click on "Turn off reminders", they are redirected to the "Method Not Allowed" page and the subscription of the events notifications remains turned on. 

Steps to Reproduce

1. Set up your mail server for Confluence notifications under General Configuration > Mail Servers
2. Browse to Calendars in the Confluence header
3. Create a new Calendar
4. Define a new event with a Start time in the next 30 minutes, and set the Reminder as "5 minutes before"
5. On the menu close to "Events," ensure the reminders are turned on.
   • If they are actually set, you will see "Turn off reminders" as a menu option.
6. Wait until you receive a mail notification in your inbox about the Event you just configured. 
7. The mail notification includes a link on the top right side called "Turn off reminder." Click this link to unsubscribe from future notifications.

Expected Results

End users are redirected to the Calendar page; and a message will confirm that the notifications/reminders are turned off. 

Actual Results

End users are redirected to the "Method Not Allowed" error page. The reminders remain turned on. 

In the Confluence Access Logs, you can see that the endpoint togglecalendarreminding.action is receiving a 405 Method Not Allowed response code: 

172.50.0.2 admin [20/Jun/2025:10:20:24 +0000] "GET /confluence/calendar/togglecalendarreminding.action?subCalendarId=416d6fed-aa05-48fe-8263-90eb7634d0fb&childSubCalendarId=ffe0c29b-1fb4-49a5-87e8-22a71d13a48b HTTP/1.1" 405 8652 100 /confluence/calendar/togglecalendarreminding.action http-nio-8090-exec-10 "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36"  ...

Workaround

Currently, there is no known workaround for avoiding this behaviour with the mail notification link. 

If an end user would like to turn off the future reminders, the user will need to log in to Confluence and browse to the specific Calendar and turn reminder emails off as described in our documentation Team Calendars > Reminders