Reamaze offers automatic spam filtering for each of your email channels. In order to manually mark conversations as spam, you'll need to first enable automatic spam filtering.
To turn on spam filtering:
Go to "Settings" and then "Channels".
Click on "Manage Settings" for the brand you wish to edit.
Scroll down until you see "Spam Filter Settings" and check the box to enable it.
Now that automatic spam filtering is turned on, you can manually mark any conversation as spam as long as that conversation belongs to a channel with spam filtering turned on.
To mark as spam, open the conversation in question and click the "Mark as spam" button. Alternatively, you may check the conversation on the main dashboard and click the "Mark as spam" button there.