A method for establishing a secure e-mail communication channel between a sender (10) and a recipient (5), wherein: 1) said sender sends an e-mail addressed to said recipient over an e-mail encryption system (16), 2) said encryption system (16) verifies in a database (160) of recipients if a public key of said recipient is available, 3) if said public key of said recipient is available, said encryption system encrypts said e-mail with said public key, and forwards the encrypted e-mail to the recipient (5), 4) if, on the other hand, said public key of said recipient is not available in said database (160), said encryption system sends instead enrolment message (1220) to said recipient, said enrolment message containing an invitation for said recipient to choose among one of the following options: i) access to said email over a secured web mail interface, or ii) sends a reply to said encryption system from which said public key can be extracted, or ii) initiate generation of a public key on the recipient's side.