Sending
Resending to people who did not open
Giving a campaign a second chance: the new subject line, how long to wait, and warming up a sending domain.
Last updated September 2, 2026
Most people who do not open a campaign simply did not see it. Resend to non-openers sends the same email again, only to them, with a different subject line.
The settings
| Setting | What it does |
|---|---|
| Resend email subject line | The new subject. It should be different from the original — the same one in the same inbox looks like a mistake. |
| Wait before resending | How long after the original send. |
| Share of the list | What proportion of non-openers to send to. |
Two or three days is the usual wait: long enough that the first email has been missed rather than ignored, soon enough that the offer still stands.
Warming up a sending domain
A new sending domain has no reputation, and a first send of fifty thousand looks exactly like a spammer. Warm up this sending domain ramps the volume up over a period you choose, starting on the send date, so the receiving systems learn who you are gradually.
Use it for a genuinely new domain. An established one that already sends regularly does not need it.