POP3 Server version changes/bug fixes.

v0.06 11/06/98

***IMPORTANT - Please move your existing OKHOSTS, and USERS files into 
the new subfolder SYSTEM, before using this version ***

.Hopefully solved the problem where POP3 clients keep getting EOF 
 returned when trying to make a connection to the server.

.Removed the 'extra' TCP_open that was being done when a connected 
 client disconnected. Now only ever has one listen socket open for POP3 
 and one for SMTP.

.No longer closes the connection when an error occurs on the HELO 
 command. RFC821 states that the connection must only be closed upon 
 receipt of the QUIT command.

.EHLO command is now supported. Although no actual extensions are 
 currently implemented.

.All filenames referenced are now specified in lowercase, to ensure 
 compatibility with other file systems.

.New subfolder SYSTEM is required. OKHOSTS, USERS, and MSGID.SEQ must 
 be stored in here, rather than in the same folder as the program.
 
.Now actually returns a 550 Syntax error for unrecognised commands, 
 instead of 250 OK. 

.SMTP server now adds Date: and Message-ID: fields to an incoming email
 if they are not already present. Message-ID: is made up of date & 
 time plus a unique 4 digit number (stored in MSGID.SEQ).

.Closed a security loop hole. HELO must be done before RSET, MAIL, 
 RCPT or DATA is allowed.

.MAIL command must precede RCPT and DATA, and at least one valid RCPT 
 must be received before DATA is allowed.

.Only 100 RCPT <recipients> are allowed per MAIL transaction. Any more 
 results in error message '552 Too many recipients'. This is as defined 
 in RFC 821.

v0.05 03/06/98
.Name changed to POP3SMTP.

.Improved the processing of the INQUEUE. It now processes email as 
 soon as it hits the queue, and does not lock up the server entirely, 
 so that it is now able to process other requests inbetween each queue 
 entry that it processes. 

.Connection timeout now implemented for POP3 connections only.
 The timeout period can be defined in the Preferences window. If no 
 commands are received from the client in that time period then the 
 server will close the connection, and release any lock on the 
 mailbox.

.If an email cannot be delivered to a users mailbox, then a DSN is 
 sent to the originator of the message, reporting the failure.
 This could happen if a user is defined in USERS but the folder
 specified does not exist.

.Now uses variables TIME_ZONE and TIME_SUMMER from STinG's DEFAULT.CFG 
 to correctly date stamp emails with the offset from GMT.

.Emails are now stored as Mxxxxxxx.TXT instead of MAILxxxx.TXT

.The email status file Mxxxxxxx.STS is now created when the email is 
 filed in the appropriate mailbox. It contains the actual date & time 
 of filing.

.The number of users logged on in the About Window now shows SMTP 
 connections too as well as POP3 connections.

v0.04 25/05/98
.Rewritten the code behind the SMTP DATA command. When the server is 
 retrieving data from a sender it no longer blocks, but is now free to 
 process other requests from other users connected to the server.
 The receiving of data via this command should also be much faster now.

.More specific errors are now returned for the SMTP RCPT command:
 501 Syntax error in parameters or arguments
     Also applies to all other commands that require parameters.
     
 550 Requested action not taken: user is not local
     This occurs when trying to send email to a user with a host that 
     is different from the host of the machine running this server.

 550 Requested action not taken: mailbox unavailable or not found
     The user is local but is not defined in file USERS

 452 Requested action not taken: insufficient system storage
     This is reported upon encountering any file errors, when trying 
     to write to disk.
     Also applies to the MAIL command.

v0.03 23/05/98
.Basic SMTP support implemented. Only allows local posts at present.
 Please read README.TXT for details.
 
.Mailbox locking now implemented. When a user logs on, their mailbox 
 is locked to prevent multiple access. This is done by writing a .LCK 
 file in \MAIL\

.Fixed bug that was causing the server to chop the right most digit from 
 numbers ending with 0, when sending responses to POP3 commands. eg. 
 3000 would be sent as 300, but 3005 would be sent correctly as 3005.

.Number of users in About Window is now updated in realtime, whenever 
 a user logs on or off.

v0.02 20/05/98
.Changing the number of users preference had no effect.
 I'd forgotten to use it. Whoops.

.If number of users is set to 0, then it is defaulted to 1.
 Zero users are not allowed, obviously.

.Every time a user connected to the server, the slower the server 
 responded to AES events etc. This was due to using a 1 second timeout 
 on every attempt to read data from an open connection.
 This has been fixed by using a 0 second timeout, and having users 
 logged on now should have very little impact.

v0.01 17/05/98
.Initial beta release
