You can login to MailChannels as mailbox owner to view your mail logs, release quarantine messages, set up your safe senders and add to your block list.
You can either login via this link: https://app.mailchannels.com/login
or click the Manage Quarantine button in your daily digest.
You will now see the login screen. Enter your email address and MailChannels password to login.
If you don't know your password you can reset it clicking on Forgot password? link.
Type in your email address and click on the Get Reset Link button.
You will then receive an email with Reset Password link:
Type in your new password and then you will be able to log in.