Mimecast Personal Portal is a webmail portal that allows you to manage personal Permit/Block lists, review or release on-hold or rejected messages, search your personal Archive and continue to send and receive email in the event of a mail server outage or for situations when you are unable to access email.
Log In Directly: https://webmail-uk.mimecast.com
Extranet: http://extranet.ertosunhouse.com
Once you are on the Extranet page, click on Mimecast.
Enter your company email address and click next.
Enter in your password that you use to log into your company laptop or computer, and then click Log In.
You have now logged in and have access to Mimecast!