Email marketing glossary

Send-time optimisation: what it means

Delivering an email to each contact at the time they are most likely to engage, based on their past behaviour.

Send-time optimisation delivers a campaign to each subscriber at the time they are most likely to engage, rather than sending to everyone at once. The system looks at each contact’s past behaviour, typically the hours when they have opened or clicked before, and schedules their copy of the email for that hour within a set window, usually the next 24 hours.

It addresses a real problem: there is no single best time to send. A college student in Delhi may check email late at night, a shop owner in Coimbatore at 7 am before opening, and an office worker in Gurugram after lunch. Sending at 10 am suits some of them and buries the email for others under hours of newer mail.

The method depends on data. Contacts with a history of opens and clicks get a personal time; new subscribers or those with no history fall back to a default time. Because Apple Mail Privacy Protection records automatic opens when emails are fetched, open-based timing is less precise for those users, and click history is a more reliable guide where it exists.

It isn’t right for every email. A flash sale that starts at noon, an event reminder or a breaking announcement should go out at a fixed time for everyone. Send-time optimisation suits newsletters, content and evergreen offers where a few hours’ difference doesn’t matter but catching people at a good moment does.

Example

A Bhopal online library sends its weekly book picks with send-time optimisation. Readers who usually open around 6 am receive it at 6 am; those who read at 10 pm get it then. Subscribers with no history receive it at the default 9 am.

In MailNesto

MailNesto can deliver a campaign to each contact at their usual opening hour, and separately offers sending at the same local clock time in each subscriber’s time zone.

FAQ

Questions about Send-time optimisation

Does send-time optimisation really improve results?

It often helps a little for newsletters and content, especially across varied audiences. Results depend on your list and how much history it has.

What happens to new subscribers with no history?

They usually receive the email at a default time you choose, until they build up enough activity.

Is it the same as time-zone sending?

No. Time-zone sending delivers at the same local clock time for everyone; send-time optimisation chooses a different hour for each person based on behaviour.