Malicious email?

Email per se is not more perilous than other techniques used on the internet but there are some aspects that relativize this statement. While other techniques are more and more dominated by big internet companies which are able to protect their business, email is a decentralized technique as the whole internet had been in the beginning. Furthermore users have built myths around email mostly inspired by allegories deduced from the good old postal communication which lead to the same results but has been protected by law and tradition. But internet and its TCP protocol build a highly failsafe, not centralized infrastructure which is on the other hand highly vulnerable. The myths or lack of knowledge lead to an ignorance that is high-graded. As contents communicated by email are mostly more sensitive than contents communicated within messaging services or chats it is astonishing that apparently nobody or just some unheard people campaign for email security. But, and this is for you, usage of email requires cautiousness the more if you may relinquish any security measures.

In the field of email the following numerated perils might face you (the list is surely not complete):

How should we face these perils?