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Function xn_smtp

This function sends an email message to an SMTP server.

struct rcpt { 
   char               name[80]; 
}; 

typedef struct _attach_file_info { 
   char             * attach_file; 
   char             * attach_type; 
} attach_file_info; 

typedef struct _smtp_info { 
   BYTE               smtp_server_ip[4]; 
   char               reverse_path[200]; 
   char               user_name[100]; 
   char               password[100]; 
   char               from[100]; 
   char               subject[100]; 
   struct rcpt        rcpts[5]; 
   int                num_rcpts; 
   int                num_cc; 
   char             * mime_fields; 
   char             * body; 
   char             * body_file; 
   char             * attach; 
   int                attach_len; 
   attach_file_info * at; 
   int                num_attach_files; 
} smtp_info; 

int xn_smtp(smtp_info * info);

Parameters

info

Pointer to a structure containing information about the email. See below or details.

return value

Returns 0 if successful, otherwise SOCKET_ERROR. If an error occurred, call xn_getlasterror and xn_geterror_string to return the error value. Section Error Codes further describes each error.

Possible values for this function are:

This function sends an email message using the SMTP protocol. Any number of attachments can be sent. Any attachment not having MIME type "text/plain" will automatically be base64 encoded. The message and possible attachment(s) can either be supplied as string constants or as files. If the message body is supplied as a file or it has attachments, vf_init must be called before this function.

The various fields of structure smtp_info have the following meaning:

The fields of structure attach_file_info have the following meaning:

If _smtp_info.mime_fields contains a Content-Type header, then all _smtp_info.mime_fields are applied to the email body; if not, they are applied to the email header only (note that if the email has attachments, a multipart email is send with separate headers for the email, the body, and each attachment). If a Content-Type header is specified, the charset and a Content-Transfer-Encoding header should also be specified. If the Content-Transfer-Encoding header specifies base64, xn_smtp() will encode the body for you.

Example:

mail->mime_fields = "Content-Type: text/plain; charset=\"iso-8859-1\"\r\n" 
                    "Content-Transfer-Encoding: 8bit\r\n";

Supported Content-Transfer-Encodings are 7bit, 8bit, base64, and quoted-printable, but only base64 will make xn_smtp() perform any transcoding.

If no Content-Type is specified by the application, the following default is applied:

Content-Type: text/plain; charset=us-ascii 
Content-Transfer-Encoding: 7bit

Example MailDemo shows how messages can be sent using this function.

SMTP Client

SMTP Configuration