From the dash board click on Email notification at the bottom, From there you can find Email Manager option.
Click on Email Manager It will redirect you to the Email manager page on that select draft an email.
On tenants you can select the category's of tenants.
You can choose the template.
After selecting the template you can choose your tenant or all the tenants.
After selecting the tenants you can see the tenants Email on the send to list.
You can see the selected template at the bottom of the page.
If you click on preview it will take you to the preview page, send email will send to all the selected tenants & cancel will abort emails.