My email campaign has been "sending" for a long time. Is it stuck?

Campaigns go out in batches of about 200 emails a minute, so large lists take a while. On Marketing → Email Campaigns, the Recipients column shows progress, for example 1,200/2,000 sent.

If the number has stopped growing:

• Check Settings → Web Settings → Email Provider. If your monthly allowance ran out, the campaign pauses and carries on by itself once more emails are available (a top-up, an upgrade or the reset on the 1st).
• Some addresses can fail; they are counted under Failed and the rest keep going.

It switches to Sent once every recipient has been tried.