EXPP5050 - Customs Handling of Import and Export Freight (CHIEF) export declarations: store and forward messaging

Note: This manual is under review following Brexit and is likely to be withdrawn. If there is anything within this manual you use regularly, please email hmrcmanualsteam@hmrc.gov.uk to let us know. Please check the other guidance available on GOV.UK from HMRC.

Store and forward messaging is the means of communication adopted for email and follows the example of conventional postal services. Email systems have a number of common features:

• a network of interconnected computers that specialise in transporting ‘envelopes’ containing messages from source to destination. Each envelope bears sender and recipient addresses and the network of computers use this information to route each ‘envelope’ across the network
• mailboxes provide the interface between the network that transports the envelopes and the end users who creates and reads the messages. Each user has their own mailbox which enables both the dispatch and receipt of envelopes, and
• eXtensible Mark Up Language (XML) messages may be sent via an Application Service Provider who will reorder the data to suit the client’s system requirements.