Spam is the abuse of any electronic communications medium to send unsolicited messages in bulk. The most common form of spam is that delivered in e-mail as a form of commercial advertising.

Three characteristic’s of the spam:

• the same information is sent to the large public,
• the message is unsolicited,
• from the message content we know that the sender’s profit will be out of proportion to the receiver’s profit.

Two kinds of spam:

• commercial: forbidden by directive UE 2000/31/EC - Unsolicited Commercial Email (UCE),
• non commercial: (UBE – Unsolicited Bulk Email) not jet forbidden by UE