We are not offering a spam filter per se, but a Spam Management tool relying on your provider spam filter: Your provider has special software that detects suspicious emails and puts them in spam. That will be reflected in BlueMail as well as the web client of the provider.
Any settings done in BlueMail complements your provider’s actions, and we cannot undo or override your provider. So essentially:
If you Block a Sender in BlueMail, you can then Unblock this address or domain to trust them again.
However, if your provider’s filter identified something as spam, it will move the emails to the Spam folder and we will not be able to change this. Even if we tried, your provider would move it back to spam.
To Unblock a Sender that was Blocked using BlueMail’s Spam feature, Go to the Spam folder | Open an email | Tap the 3-dot-menu | Unblock Sender | confirm with OK.