,-----------------.   ,--------------.                                                                                                                                            
                                                                                                                                                      |/usr/bin/sendmail|   |Daemon        |                                                                                                                                            
                                                                                                                                                      |-----------------|   |--------------|                                                                                                                                            
                                                                                                                                                      |Postfix - Modul  |   |├── proxymap  |                                                                                                                                            
                                                                                                                                                      |"postdrop"       |   |└── proxywrite|                                                                                                                                            
                                                                                                                                                      `-----------------'   `--------------'                                                                                                                                            
                                                                                                                                                               |                                                                                                                                                                        
                                                                                                                                                               |                                                                                                                                                                        
                                                                                                                                                        ,------------.                                      ,----------.   ,------------.  ,-----------.   ,-----------------.   ,-----------------.   ,---------------.                
                                                                                                                                                        |Queue       |                                      |Daemon    |   |Daemon      |  |Daemon     |   |MTA - MTA Verkehr|   |MUA - MSA Verkehr|   |Daemon         |                
                                                                                                                                                        |------------|                                      |----------|   |------------|  |-----------|   |-----------------|   |-----------------|   |---------------|                
                                                                                                                                                        |└── maildrop|                                      |└──  anvil|   |└──  dnsblog|  |└──  verify|   |TCP/IP - Port 25 |   |TCP/IP - Port 587|   |└──  postscreen|                
                                                                                                                                                        `------------'                                      `----------'   `------------'  `-----------'   `-----------------'   `-----------------'   `---------------'                
                                                                                                                                                               |                                                                                                     |                     ---------------                              
                                                                                                                                                               |                                                       ,-----------------------------------.         |                                                                  
                                                                                                                                                               |                                                       |Lookup Table access_client         |         |                                                                  
                                                                                                                                                               |                                                       |-----------------------------------|         |                                      ,--------------------------.
                                                                                                                            ,----------.  ,----------.   ,----------.                                                  |Lookup Table access_recipient      |   ,---------.                ,-------------.   |Realtime Blockhole Lists  |
                                                                                                                            |Daemon    |  |Daemon    |   |Daemon    |                                                  |Lookup Table access_recipient-rfc  |   |Daemon   |                |Daemon       |   |--------------------------|
                                                                                                                            |----------|  |----------|   |----------|                                                  |Lookup Table access_sender         |   |---------|                |-------------|   |von einliefernden Hosts   |
                                                                                                                            |QMQP-Modul|--|└──  qmqpd|   |└── pickup|                                                  |Tabellen zum Black- und Whitelisten|---|└── smtpd|                |└──  tlsproxy|   |reverse DNS-Abfrage z.B.  |
                                                                                                                            `----------'  `----------'   `----------'                                                  |an Hand der IP-Adrese, Hostname,   |   `---------'                `-------------'   |bei SPAMHAUS              |
                                                                                                                                                                                                                       |Empfänger oder Sender              |                                                |                          |
                                                                                                                                                                                                                       |                                   |                                                `--------------------------'
                                                                                                                                                                                                                       `-----------------------------------'                                                                            
                                                                                                                                                                                                                                                                                                                                        
                                                                                                                                                                 ------------------------------------------------------------------------------------------------                                                                       
                                                                                                                                                                                         ,-----------------------------------.   ,------------------------------.   ,--------------------------------.                                  
                                                                                                                                                 ,-----------.   ,-------------------.   |Lookup Table relocated_maps        |   |Lookup Table canonical_maps   |   |Lookup Table virtual_maps       |  ,-----------.                   
                                                                                                                                                 |Daemon     |   |Daemon             |   |-----------------------------------|   |------------------------------|   |--------------------------------|  |Daemon     |                   
                                                                                                                                                 |-----------|   |-------------------|---|mit Angabe der neuen eMailadresse  |   |Umschreiben von nicht-lokalen |   |aller lokalen, virtuellen und   |  |-----------|                   
                                                                                                                                                 |└── cleanup|   |└── trivial-rewrite|   |bei verzogenen Accounts.           |   |Empfängeradressen             |   |entfernten eMailadressen        |  |└──  tlsmgr|                   
                                                                                                                                                 `-----------'   `-------------------'   |                                   |   |                              |   |                                |  `-----------'                   
                                                                                                                                                                                         `-----------------------------------'   `------------------------------'   `--------------------------------'                                  
                                                                                              -------------------------------------------                                                                                                                                                                                               
                                                              ,----------------------------.  ,----------.                                                                   ,---------.                                                                                                                                                
                                                              |Lookup Table  transport_maps|  |Daemon    |   ,---------.   ,------------.   ,-----------.   ,------------.   |Agent    |   ,----------.                                                                                                 ,-----------.                   
                                                              |----------------------------|  |----------|   |Daemon   |   |Agent       |   |Modul      |   |Queue       |   |---------|   |Daemon    |                                                                                                 |Daemon     |                   
                                                              |Weiterleitung an einen      |  |├── bounce|   |---------|   |------------|   |-----------|   |------------|   |├── error|   |----------|                                                                                                 |-----------|                   
                                                              |weiteren (finalen) MTA.     |  |├── defer |   |└── flush|   |└──  discard|   |└── resolve|   |└── incoming|   |└── retry|   |└──  showq|                                                                                                 |└──  scache|                   
                                                              |                            |  |└── trace |   `---------'   `------------'   `-----------'   `------------'   `---------'   `----------'                                                                                                 `-----------'                   
                                                              `----------------------------'  `----------'                                                                                                                                                                                                                              
                                                                                                                                                                                                                                                                                                                                        
                                                                                                                                                                                                                                                                                                             ,-------------------------.
                                                                                                                                     ,------------.   ,--------.                                                                                                                              ,----------.   |Lookup Table generic_maps|
                                                                                                                                     |Daemon      |   |Daemon  |                                                                                                                              |Mailclient|   |-------------------------|
                                                                                                                                     |------------|   |--------|                                                                                                                              |----------|   |von eMailadressen        |
                                                                                                                                     |└──  virtual|---|└── qmgr|------------------------------------------------------------------------------------------------------------------------------|└── smtp  |---|beim Versenden.          |
                                                                                                                                     `------------'   `--------'                                                                                                                              `----------'   |                         |
                                                                                                                                                           |                                                                                                                                        |        `-------------------------'
                                                                                                                                                           |                                                                                                                                        |                                   
                                                                                                                                                    ---------------------------------------------                                                                                                   |                                   
                                                                                                                                                           |                                                      ,------------------------------.                                 ,-------------------------------.                    
                 ,----------.       ,----------.   ,--------------------------------------.   ,--------.  ,-------------------------------------.   ,-----------.   ,----------.   ,------------.   ,---------.   |Lookup Table /etc/aliases     |                                 |MTA                            |                    
                 |Mailclient|       |Mailclient|   |Lookup Table lmtp_generic_maps        |   |Queue   |  |Lookup Table .forward                |   |Queue      |   |Queue     |   |Queue       |   |MDA      |   |------------------------------|                                 |-------------------------------|                    
                 |----------|       |----------|   |--------------------------------------|   |--------|  |-------------------------------------|   |-----------|   |----------|   |------------|   |---------|   |an lokale Empfänger zugewiesen|                                 |(Mail Transport Agent)         |                    
                 |└── pipe  |       |└── lmtp  |---|eMail-Adressen im Envelope und Header |   |└── hold|  |automatischen Anwesenheitsnachrichten|   |└── corrupt|   |└── active|   |└── deferred|   |└── local|---|werden können.                |                                 |andere SMTP-Server (Relayhosts)|                    
                 `----------'       `----------'   |                                      |   `--------'  |                                     |   `-----------'   `----------'   `------------'   `---------'   |                              |                                 |im Internet bzw. Intranet      |                    
                                                   `--------------------------------------'               `-------------------------------------'                                                        |        `------------------------------'                                 |TCP/IP - Port 25               |                    
                                                                                                                                                                                                         |                                                                         `-------------------------------'                    
                                                                                                                                                                                                         |                                                                                                                              
,------------------------------.  ,---------------------.                                                                                                                                       ,-----------------.                                                                                                                     
|Mailman                       |  |MDA                  |                                                                                                                                       |mailbox          |                                                                                                                     
|------------------------------|  |---------------------|                                                                                                                                       |-----------------|                                                                                                                     
|Weitergabe der eMail          |  |(Mail Delivery Agent)|                                                                                                                                       |Postfix - Queue  |                                                                                                                     
|an Mailinglisten / wie Mailman|  |Dovecot IMAP-Server  |                                                                                                                                       |"mailbox"        |                                                                                                                     
|oder via UUCP ...             |  |TCP/IP - Port 24     |                                                                                                                                       |lokale Zustellung|                                                                                                                     
`------------------------------'  `---------------------'                                                                                                                                       `-----------------'