Programming

Hey Guys,
I am writing an SMTP mail client in c++ in unix and it needs to do the following:
I have written the smtpclient class, but I am drawing blanks on the rest. I am going to include the smtpclient class below ,but I was hoping for some pointers or help on the rest of the program.

Class smtpclient (

public String smtpClient (String machineName, int portNumber);
public String login (String userName, String password);
public void logout ():
public String senderAndReceiver (String sender, String receiver);
public String messageBodyPrefix (String message);
public String messageSuffix (String message);

If you've already written the class for this, points 1 and 2 should already be checked off. Point 3 should only be a simple sequence of new -> login -> senderAndReceiver -> messageBodyPrefix -> messageSuffix -> logout
Although, and please correct me if I'm wrong, but you seem to have methods for the message prefix (does that mean the header?) and the suffix (common signature for all mails?), but which method transfers the content itself?