How to add whitelist in mailbox

1. Outlook

Step 1: Sign in your Outlook (Make sure that you use the web browser.)

Step 2: Make sure Beta is turned off.

Step 3: Go to the setting wheel and click on "options".

Step 4: Go to safe mailing lists.

Step 5: Add following TOPBTC.COM official email one by one and make sure that you click "save" after.
support@mail.topbtc.com 
support@mail.topbtc.one

2. Gmail
Step 1: Log in your google Gmail.
Step 2: Go to "settings" and click settings on the top right.

Step 3: Go to "filters and Blocked addresses".

Step 4: Click "create a new filter".

Step 5: Add the email in the “From” box and press "create a filter with this search".
Repeat this step for every TOPBTC.COM official email:
support@mail.topbtc.com 
support@mail.topbtc.one


Step 6: Check the box “Never send it to Spam” and then create the filter.