I'm not sure if it helps, but I"ve been noticing almost all of these "no adress" senders actually use the adress : <email AT enews.electrabel.com>
You can make two rules to rule them out :
Create a rule with :
Add condition : From > email AT enews.electrabel.com
Add action : Delete
(or, mark as spam)
Create a rule with :
Add condition : All messages
Add action : Delete (or mark as spam)
Add exception : If mail adress holds an > @
These two rules should help.
Feel free to use the 3 dots on the top right corner of the mail (make sure you never click anything in the mail itself),
and select "Show message as source", there you will be looking for :
Date : 'the date of sending'To : 'You'
From : .... (Here you will find the email used)You can also find the IP¨of the sender and trace it back