Controlling how survey email invitations are sent

When you send a survey, invitations go out to everyone at once by default. Most organisations' email systems handle this without any trouble.

Some do not. If your organisation's email gateway limits how many messages it will accept in a short space of time, a large send can be slowed down, held, or in some cases rejected outright, and some of your people never receive their invitation. If that has happened to you, we can send your invitations in smaller batches, spaced out over time, so they arrive steadily rather than all at once.

How to set this up

These settings are applied by us rather than by you. To turn them on, contact your Account Manager or our support team and let us know:

• How many invitations should go in each batch. The default is 99.
• How long to wait between batches, in minutes. The default is no wait, which is why invitations currently all go at once.

If you are not sure what to ask for, your IT team will know what your email system allows. The question to put to them is how many external emails your gateway will accept from one sender in a short period. This applies to email invitations. SMS invitations and passcode distribution are not affected.

What happens once it is set up

Your invitations are divided into batches of the size you chose. The first batch sends immediately when you publish your survey. Each batch after that waits its turn, spaced by the delay you chose.

So if you have 1,000 participants, batches of 100, and a five minute delay:

The whole send takes about three quarters of an hour, and your email system receives a manageable number of messages at a time instead of a thousand at once.

Following the send

While a send is in progress you will see two statuses on participant tracking:

• Pending: this invitation is part of a batch that has not sent yet. It is queued and nothing is wrong.
• Sent: this invitation has gone.

Pending invitations move to Sent as each batch goes out. If you are watching the tracking page shortly after publishing, expect to see a mixture of the two. This is the point of the feature working, not a sign of a problem.

Choosing your settings

There is no single right answer, and it is worth erring on the cautious side the first time.

• A smaller batch size puts less pressure on your email system, but the whole send takes longer.
• A longer delay does the same.
• Bear in mind how long the full send will take. Batches of 50 with a ten minute delay across 2,000 participants means the last person receives their invitation more than six hours after the first. If your survey opens on a Monday morning, some of your people are hearing about it after lunch.

A good place to start is to keep the batch size close to your gateway's limit and use the shortest delay that keeps you under it. We can adjust the settings between surveys once you have seen how the first send behaves.