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Function xn_smtp_ex

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_ex(smtp_info * info, byte * server_ip, word port, dword flags);

Parameters

info

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

server_ip

The SMTP server's IP address in network byte order.

port

TCP port number to connect to in little endian format. If this parameter is 0, default value 587 for secure and CFG_SMTP_PORT (default: 25) for unsecure connections is selected. Please note that many SMTP servers require the non-standard port value 465 for secure connections.

flags

0 or SMTP_SECURE for a secure connection.

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

If flag SMTP_SECURE is applied, this function requires an initialization of RTIP-32's SSL/TLS support.

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

SMTP Client

SMTP Configuration

Function xn_smtp