Method for entrusting blockchain transactions contents, wherein at least one transmitting user configured to interact with a trusted entity connected to a ledger of a blockchain, the method comprising: • sending from the transmitting user to a recipient user: ∘ an electronic message related to a a transaction concerning an electronic message or any of the events and contents related therein through an initial route, ∘ a copy of said electronic message to a certification system through a second route, • receiving said copy of the electronic message at the certification system, • sending from the certification system to the destination message server of the recipient a second electronic message comprising the copy of the electronic message, so the destination message server of the recipient receives: ∘ the electronic message through the initial route, and ∘ the copy of the electronic message through the second route, wherein the second electronic message comprising the copy of the electronic message, • receiving in the incoming message server of the certification system data relative to the delivery of the second electronic message sent to the destination message server of the recipient, • generating at the certification system an electronic document comprising data related to at least one of: ∘ the electronic message, ∘ the copy of said electronic message to the destination message server of the recipient, ∘ data relative to the delivery of the second electronic message to the destination message server of the recipient and • applying a digital signature to the electronic document of the previous step for the creation of an electronic certificate, the method being characterised by comprising, in at least one of the previous steps, further submitting the result of the signed electronic document to the trusted entity to feed a smart contract wherein said trusted entity feed the smart contract with the electronic certificate; said trusted entity submitting information to a blockchain to be used by smart contracts. • sending from the transmitting user to a recipient user: ∘ an electronic message related to a a transaction concerning an electronic message or any of the events and contents related therein through an initial route, ∘ a copy of said electronic message to a certification system through a second route, ∘ an electronic message related to a a transaction concerning an electronic message or any of the events and contents related therein through an initial route, ∘ a copy of said electronic message to a certification system through a second route, • receiving said copy of the electronic message at the certification system, • sending from the certification system to the destination message server of the recipient a second electronic message comprising the copy of the electronic message, so the destination message server of the recipient receives: ∘ the electronic message through the initial route, and ∘ the copy of the electronic message through the second route, wherein the second electronic message comprising the copy of the electronic message, ∘ the electronic message through the initial route, and ∘ the copy of the electronic message through the second route, wherein the second electronic message comprising the copy of the electronic message, • receiving in the incoming message server of the certification system data relative to the delivery of the second electronic message sent to the destination message server of the recipient, • generating at the certification system an electronic document comprising data related to at least one of: ∘ the electronic message, ∘ the copy of said electronic message to the destination message server of the recipient, ∘ data relative to the delivery of the second electronic message to the destination message server of the recipient and ∘ the electronic message, ∘ the copy of said electronic message to the destination message server of the recipient, ∘ data relative to the delivery of the second electronic message to the destination message server of the recipient and • applying a digital signature to the electronic document of the previous step for the creation of an electronic certificate,