user doc: Updated example based on info from Andrea.
@@ -23,9 +23,16 @@ interval for checking for messages, enter a number and select its time unit.
. In the *Maximum Messages to Retrieve* field, accept the default of 10 or
indicate the maximum number of messages that the connection can return for
each poll. If the connection finds more than this number of unread messages,
-then it returns the most recent messages. For example, if you accept the
-default of 10 and there are 15 messages then the connection returns the
-10 most recent messages. The connection returns a particular message only once.
+then it returns the most recent messages.
+The connection returns a particular message only once.
++
+For example, if you accept the default of 10 and there are 15 messages at
+the time of a poll then the connection returns the 10 most recent messages.
+At the next poll, the connection checks for messages that have a time stamp
+that is after the most recent message that the connection previously returned.
+This means that the 5 messages that were not returned in the first example
+poll are never returned.
+
+
When a Slack connection returns more than one message, the integration
processes the messages as a batch. In other words, {prodname} executes
