When you are using Opinio invitations, the general process is as follows:
You can have as many invitations as you like per survey. Sometimes it is helpful to divide your invitees up in groups. Or perhaps you want to send your invitations in bulks with different dates and times. You do that by using more than one invitation. Each invitation may have an unlimited number of invitees. Please note that Opinio does not currently check for duplicate email addresses across invitations.
If you edit an active invitation, it becomes inactive and you must re-activate it after saving your changes. It is done this way to prevent erroneous modifications and give the author a chance to verify all the values, particularly on the details screen displaying the schedule.
You can add invitees to your invitation at any time, even after you have activated it. If your initial invitation message is already sent, and you have one or more reminders scheduled, you can still add invitees. Once the next reminder is sent out, your new invitees will also receive their message, but they will receive the initial invitation message, not the reminder message. In this scenario, invitees will receive one message less than the invitees that were added before the initial send date. In other words, the later the invitees are added, the fewer reminder messages they will receive. After you have added invitees in the middle of your schedule like this, you do have the option of sending the invites right away instead of waiting for the next reminder date. You can go to the "manage invitees" screen. If you have added more invitees, you will see the option "Send invitation to new invitees now" above the list of invitees. You can click on this, specify the message, and then send the invitation to the new invitees.
An invitation has three different messages: the invitation message, the reminder message and the last reminder message. Opinio determines what message to send at any given time based on where we are in the schedule (current date/time versus the dates/times in the schedule), but also what messages have been sent to the invitees. An invitee will not get a reminder message (or the last reminder message) if the initial invitation message has not been sent to him/her yet. In such a case, the invitee will receive the initial invitation message instead of the reminder. If you have multiple reminders specified, Opinio distinguishes between the reminder message and the last reminder message. The last reminder message will be used if there are multiple reminder dates specified and the reminder about to to be sent out is the last one.