<Dd> One of Postfix' many daemons serving exactly one purpose . This split - up into many smaller pieces of software is considered one of the reasons why Postfix is secure and stable . </Dd> <Dd> The blue boxes represent so - called lookup tables . A lookup table consists of two columns (key and value) containing information used for access control, e-mail routing etc . </Dd> <Dd> The yellow boxes are either mail queues or files . In either case, e-mails are stored on persistent media (e.g., a hard disk). </Dd> <Dd> The clouds stand for points at which e-mails enter or leave Postfix . For example, smtpd receives mail from other mail servers or users whereas smtp relays mail to other MTAs . </Dd>

Where does the postfix unix mail server store e-mail ​