Block one email

Hi, how can I block one email?
I am told 'go to the gear sign, or the 3 dots—That is not on mine.

See extract from eM Client support page.

Block emails in eM Client

Creating a blacklist for emails in eM Client takes no more than a few simple clicks, thus saving time and maximizing your productivity.

Right-click on the message from the sender that you would like to block.

Hover over Move to Junk and select Move to Junk and blacklist email or Move to Junk and blacklist domain.

To view and manage the Blacklist rule:

Head to Menu > Rules
Select the Blacklist rule and click the Edit button
A new window will then pop up and you can add new items or remove any of the email addresses and domains already in it.

Also see the following thread with screenshots

Blacklist unwanted emails