PopGetHeaderValue Function  
 
INT WINAPI PopGetHeaderValue(
  HCLIENT hClient,  
  UINT nMessageId,  
  LPCTSTR lpszHeader,  
  LPTSTR lpszValue,  
  INT nMaxLength  
);

The PopGetHeaderValue function returns the value of a header field in the specified message.

Parameters

hClient
Handle to the client session.
nMessageId
Number of message to retrieve header value from. This value must be greater than zero. The first message in the mailbox is message number one.
lpszHeader
Pointer to a null-terminated string which specifies the message header to retrieve. The colon should not be included in this string.
lpszValue
Pointer to a string buffer that will contain the value of the specified message header.
nMaxLength
The maximum number of characters that may be copied into the buffer, including the terminating null-byte.

Return Value

If the function succeeds, the function returns the length of the header field value. If the header field is not present in the message, the function will return a value of zero. If the function fails, the return value is POP_ERROR. To get extended error information, call PopGetLastError.

Remarks

The PopGetHeaderValue function returns the value of a header field from the specified message. This allows an application to be able to easily determine the value of a header (such as the sender, or the subject of the message) without downloading the entire header block or contents of the message.

This function uses the XTND XLST command, which is an extension to the POP3 protocol. Not all servers support the use of this command. If this command is not supported by the server, the function will attempt to retrieve the entire message header and return the value for the specified header field. This enables an application to use this function even if the server does not support command extensions.

Requirements

Client: Requires Windows 7, Windows Vista or Windows XP.
Server: Requires Windows Server 2008 or Windows Server 2003.
Header: Include cstools7.h.
Library: Use cspopav7.lib.
Unicode: Implemented as Unicode and ANSI versions.

See Also

PopGetMessageHeaders, PopGetMessageId, PopGetMessageSender