An autoresponder is a way of automatically replying to messages as they arrive in a user's mailbox.
In VPOP3, an incoming message must arrive in a user's mailbox for the autoresponder to trigger. If you use forwards, assistants, mappings, etc to divert a message before it arrives in the mailbox, the autoresponder will never trigger. If you want to use an autoresponder, but not keep the original message, then make sure the message arrives in the mailbox (eg by using an 'Assistant' rather than a 'Forward', with the 'Redirect to assistant' option off), but turn off the 'Keep original message' option in the autoresponder settings. This will make the autoresponder delete the original message after responding to it.
For Versions 3 and 4 see Autoresponders v3 & v4
In VPOP3 version 5, the autoresponder system has changed from previous versions. It is now a lot more flexible, but this does mean that it is slightly more complicated.
In version 5, you can create multiple autoresponders for a single user, and create multiple conditions for each autoresponder to say when it should act.
For instance, you could create three different autoresponders, one for evenings, one for weekends, and one for your holidays, and have different text (and other actions) with each of them, then for your holiday autoresponder you could configure all your holidays for the year ahead, so it will automatically turn on and off at the appropriate times.
To create an autoresponder, edit the user, and go to the Autoresponder tab
In the Autoresponders: drop-down at the top (1), choose the existing autoresponder name (if any) or <New> to create a new autoresponder. Usually it will select this autoresponder automatically, but if it doesn't, pressing Go will select the autoresponder, and show the rules which will trigger the autoresponder in the table beneath (2).
Note that this drop-down only selects which autoresponder you are currently editing. It does not select which autoresponder is used; all the defined autoresponders are used, depending on the rules defined for the autoresponders.
Pressing Edit will take you to the page where you can edit the autoresponder definition. This contains the text of the autoresponder, attachments, headers, whether the original message should be copied to another user, and so on.
Once you have defined the autoresponder, you can create the 'rules'
Each autoresponder you have defined can have zero or more rules
Each autoresponder rule tells the autoresponder when to trigger. If any of the rules match the conditions, then the autoresponder will trigger.
By default, when you create a new autoresponder, it will have a single rule which will always trigger.
You can see the list of rules, add new rules or delete existing rules. If there are no rules for the autoresponder, it will never trigger.
To edit an existing rule, just double-click on it in the list.
If you leave any (or all) of the conditions blank (except for 'Days of the Week'), then that condition will not be checked (so you can leave all the conditions blank, to have the autoresponder always trigger)
The Dates, Times and Date/Time settings are sometimes a bit confusing because people may think that Dates + Times is equivalent to Date/Time, but they are different.
If you have Dates of 1 March 2012 - 7 March 2012 and Times of 10:00 - 14:00, then the autoresponder will trigger between 10am and 2pm on each day between 1st and 7th March (inclusive)
However, if you have Date/Times of 1 March 2012 10:00 - 7 March 2012 14:00, then the autoresponder will trigger from 10am on 1st March to 2pm on 7th March.
You can use Dates, Times and Date/Times in the same rule.