Every time VPOP3 adds a message to the Outgoing mail queue, it runs a script called outmessage.lua.

Scripts are stored as files in the VPOP3 directory in VPOP3 v6.6 and earlier, or managed through the Settings → Scripts page in VPOP3 v6.7 and later.

See the Lua Scripting page for general details about VPOP3's scripting, and information on how we can help.

For every message which is to be sent VPOP3 calls a function in that script called NewMessage.

The function signature is: NewMessage(AuthenticatedSender, ReturnPath, CreationDate, Subject, SenderIPAddress, FileLength, Priority, Headers, Message, HoldSeconds, DeleteAfterSeconds)

• AuthenticatedSender - The VPOP3 username of the user who authenticated to send the message (if authentication wasn't used, this is blank).
• ReturnPath - The email address of the sender (strictly speaking, the SMTP return path/MAIL FROM address, which is where bounce messages will be sent).
• CreationDate - The time the message was created - as YYYYMMDDHHMMSS.
• Subject - The subject of the message.
• SenderIPAddress - The IP address of the message sender (if generated from within VPOP3/forwarded/etc, this will be blank).
• FileLength - The size of the message file - this will be slightly longer than the message itself because of control data, but can be used as an estimate.
• Priority - The current priority of the message. VPOP3 will send messages with a smaller priority number first.
• Headers - A list of the message header lines in raw form.
• Message - The message content in raw form (single string, includes raw headers).
• HoldSeconds - The current number of seconds the message will be held before being sent (0 = no time).
• DeleteAfterSeconds - The current number of seconds before the message will be deleted from the queue (0 = never).

The function returns a table of new settings. This can contain the following fields. If the field doesn't exist, then the value is not changed.

• Priority - The new priority of the message. VPOP3 will send messages with a smaller priority number first.
• HoldReason - A reason to be logged in the database for why the message is held.
• Hold - If this is set to 'true', '1', 't', 'hold' then the message is held, otherwise it is not held.
• HoldUntil - If this is set to a string like YYYYMMDDHHMMSS then the message is held until that time, otherwise it is held for the specified number of seconds.
• DeleteAfter - If this is set to 'none', then it is never deleted. If this is set to a string like YYYYMMDDHHMMSS then the message will be deleted after that time, otherwise it will be deleted after the specified number of seconds.