Connecting to HTG

Publication date 01-04-2021

The following interfaces can be used to exchange messages via the HTG:

• SMTP-MTA (VPN)This interface is intended for high-frequency interaction between business and HTG. When using the SMTP-MTA interface, the company’s MTAs (mail servers) and HTG are configured so that direct SMTP traffic between the MTAs is possible (server-to-server connection).
• SMTP-MSA/POP3 (mailbox)These interfaces are intended for low-frequency interaction between business and HTG (that is, no more than 1 interaction per connection per minute) and is accessed ad hoc over a TCP / IP (internet) connection. As soon as the transactions with the interface have been completed, the connection is broken again.You can download the interface descriptions via the link at the bottom of this page.

The interface descriptions mentioned describe the standards for the exchange of messages between mail servers (MTAs), respectively for the exchange of messages between a mail client and HTG, based on SMTP-MSA and POP3.

A number of additional agreements on these standards apply to Single Window. The document ‘Interface description for Single’ Window describes these additional agreements.

From release 1.1 of the specifications, the interface has been expanded with an addition for an extra multipart/mixed MIME part (‘attachment’). The document ‘Interface description HTG Message with extra attachment’ describes this extension.

All interface descriptions are included in the documentation.

Do you have questions about connection documentation ? Please contact the National Customs Helpdesk (NHD).