Klenty includes a default 120-second interval between each email. This setting means that sending 30 emails can take an hour.
The interval helps improve email deliverability. You can change this (no lower than 30 seconds) from Settings > Deliverability.
The reason we kept 30 seconds as a minimum is that when a user sends a group of emails every 30 secs, the mail servers may detect the emails as bots, causing the emails to end up in the spam folder.
When facing deliverability challenges, we recommend changing this to Random.