Network News Transfer Protocol  

The Network News Transfer Protocol (NNTP) control enables applications to access a news server, list the available newsgroups, retrieve articles and post new articles. It is common for this control to be used in conjunction with the Mail Message control to construct the articles, since a news article uses the same general format as an email message.

The following properties, methods and events are available for use by your application:

Initialize the control and validate the runtime license key for the current process. This method is normally not used if the control is placed on a form in languages such as Visual Basic. However, if the control is being created dynamically using a function similar to CreateObject, then the application must call this method to initialize the component before setting any properties or calling any other methods in the control.

Establish a connection to the NNTP server. Once the connection has been established, the other methods in the control may be used to access the newsgroups and/or post new articles to the server.

Provide a user name and password to authenticate the client session. This should only be used if required by the server. Not all news servers require authentication, and some only require authentication when posting articles. If you attempt to perform a function that requires authentication, an error will be returned that indicates you should authenticate and then retry the operation.

Disconnect from the server and release any resources that have been allocated for the client session. After this method is called, the client session is no longer valid.

Unload the Windows Sockets library and release any resources that have been allocated for the current process. This is the last method call that the application should make prior to terminating. This is only necessary if the application has previously called the Initialize method.


News articles are posted in hierarchical groups, similar to how files are stored in folders. Each level in the newsgroup hierarchy is separated by a period, so newsgroup names look like This is Microsoft's newsgroup for articles about Visual C++ programming. Additional subgroups are used to further narrow the topic; for example, there's the newsgroup for third party tools and components for Visual C++, and the newsgroup which discusses issues related to the Active Template Library. The NNTP control provides the following methods for accessing newsgroups on the server:

This method requests that the server return a list of all of the newsgroups that are available. The application can also request that only groups which were created since a specific date should be returned. This allows the application to maintain a list of newsgroups on the local system, and then use this method to periodically update that list based on the date it was last modified. If the method is successful, the application should call the GetFirstGroup method to begin processing the group list.

This event is generated for each newsgroup returned by the ListGroups method. Information about the group is passed to the event handler as arguments to the event, including the name of the group, the first available article number and the last available article in the group.

This method is used to select a newsgroup as the current group. Once selected, the application has access to the articles in that newsgroup.

News Articles

News articles are the messages posted to one or more newsgroups. Articles are referenced by their article number, which is a value assigned by the news server. These articles have a structure that is the same as an email message, with some slightly different headers. Because of this, you can use the Mail Message interface to parse articles that you retrieve, as well as create new articles to post to the server. The following methods are used to access and create news articles:

This method requests that the server return a list of articles that are available in the current newsgroup. The application can request that all articles be returned, or only those articles which fall into a certain range of article numbers.

This event is generated for each article returned by the ListArticles method. Information about the news article is passed to the event handler as arguments to the event, including the article ID, size, subject, author and date that the article was posted.

Retrieve an article from the server, storing the contents in a string buffer or byte array. This can be used to process the contents of an article without the overhead of storing it in a file on the local system.

Retrieve an article from the server and store it in a file on the local system.

This method posts an article to one or more newsgroups on the server. A newsgroup article is similar to an email message, and the MIME interface may be used to create the article headers and body. One important difference is that the message must contain a header named "Newsgroups" with the value set to the newsgroup or newsgroups that the article should be posted to; multiple newsgroups should be separated by commas. If this header is not defined, the posting will be rejected by the server and the method will return an error. You should also be aware that some servers limit the number of newsgroups that a message can be posted to. When an article is posted to more than one newsgroup at a time, this is called cross-posting. Current convention says that an article should not be cross-posted to more than five newsgroups at a time. Also keep in mind that multi-posting (posting the same article to different newsgroups separately) is generally discouraged and should never be done on USENET.

Attaching Files

It is possible to attach files to newsgroup articles; however it should only be done if it is considered appropriate for the group. Many newsgroups have their own acceptable use policies which determine whether or not file attachments, particularly large binary files, are acceptable. If the newsgroup accepts attachments, you can use one of several methods for posting files. It is recommended that you use the File Encoding control to handle the actual encoding of the data.

A uuencoded file attachment is included directly in the body of the message. Because the MIME interface creates a multipart message even when uuencoding is specified, the File Encoding control should be used to encode the data and then it should be included in the main body of the message.

A Base64 file attachment has the same structure as what is used by email messages. This requires that a multipart message be created, with the encoded data attached as a part of the message. You can use the MIME control to create this kind of message. Note that not all third-party newsreaders correctly handle multipart messages.

An encoding method commonly used on USENET, it's similar to uuencoded attachments where the file data is part of the body of the message. The File Encoding control should be used to encode the data and then it should be included in the main body of the message. More information about yEnc encoding can be found at