Email notification is a feature of the MediaWiki software on which Wikipedia runs. It allows editors who have registered an account and provided an email address to receive automatic email notifications when their user talk page is changed. Note that once an email notification has been sent, additional talk page changes will not result in any further notifications, until the user has logged in and visited their talk page. In addition, the user's own page changes never trigger a notification mail to themselves.
The feature is activated by default on the English-language version of Wikipedia (since May 2011) and can be deactivated by editors who prefer not to receive notifications, in the Email options part of the User Profile section of their user preferences. Emails are sent from the address email@example.com.