CSSCurrent en:Verification modes
The verification process assures that the email address a sender is using is in fact the senders email address. How the sender is verified depends on the verification mode. There are two verification modes: sender verification and client verification mode. In both modes, the verification is connected to the sender. It differs only in the process of creation.
When the sender uses this mode, the email address is verified by themself. An email with a verification code will be sent to the sender the first time he is using the system. This code needs to be copied from the email and pasted into a field in the user interface to allow confirmation of the email address. When an user send an transfer via the Web App he automatically uses sender verification.
When the sender uses this mode, the email address is verified automatically by the client. When a client is removed from the server, also the verifications created by this client get lost.
With the introduction of QUICK, the verification has become even more important. To create a QUICK connection, the sender and the recipient must have a verification. With server version 4.5.0 QUICK can be used in both modes. In previous server versions, QUICK only worked with sender verification mode. The user can activate a QUICK connection themself, regardless of which mode the verification was created in.