[hurtuvac78]

Can one guess printers email addresses and start spamming random printers?

I dont see any way to register the sender's expected email on the printer. Back to fax spamming...?

[sct202]

Someone did that to my old HP printer a couple times, but there were settings to only accept emails from specific addresses that I eventually turned on.

[risfriend]

Well you can customise it with the brother printer. Brother itself registers your unique email id against your registered device, hence it has to be globally unique.