We can not get the correct user name(now it is the empty value) when an email comment notification is post
Precondition:

• Login system by user: 'superuser'
• Add comment component to history page
• Configure observation and mail tool to be ready for sending page comments notification
• Add a comment for history page on public or author instance
• Watch the mail notification on your 'mailTo' email address
• You will see the page comments notification email, the mail content is:

has posted new comment for page History.
Click here to review the message.

• The correct mail content should be the following:

superuser has posted new comment for page History.
Click here to review the message.