context.puml

!include <c4/C4_Context.puml>  

'ref http://plantuml.com/stdlib
!include <office/Users/user.puml>
!include <office/Users/mobile_user.puml>

'LAYOUT_WITH_LEGEND

title System Context diagram for Internet Banking System

Person(customer  , Customer , "<$user> <$mobile_user>\n A customer of the bank, with personal bank accounts", $link="${action-uri/nasdanika://customer}")

System(banking_system, "Internet Banking System", "Allows customers to view information about their bank accounts, and make payments.", $link="${action-uri/nasdanika://internet-banking-system}")

System_Ext(mail_system, "E-mail system", "The internal Microsoft Exchange e-mail system.", $link="${action-uri/nasdanika://e-mail}")
System_Ext(mainframe, "Mainframe Banking System", "Stores all of the core banking information about customers, accounts, transactions, etc.", $link="${action-uri/nasdanika://mainframe}")

Rel(customer, banking_system, "Uses")
Rel_Back(customer, mail_system, "Sends e-mails to")
Rel_Neighbor(banking_system, mail_system, "Sends e-mails", "SMTP")
Rel(banking_system, mainframe, "Uses")