SASLMechanisms is a TIdSASLList property that identifies the Simple Authentication and Security Layer (SASL) authentication mechanisms supported on the connection to the remote IMAP4 server. 

SASLMechanisms is updated in the Login method when the AuthType property contains the value atSASL, and the Capabilities property includes the AUTHENTICATE directive that indicates supports for the feature on the remote IMAP4 server. 

For additional information about SASL authentication, please refer to the following documentation: 

IANA Official Simple Authentication and Security Layer Mechanisms  

Login Capabilities AuthType