| MailChimp | 105,698 | https://mailchimp.com |
| Klaviyo | 80,500 | https://www.klaviyo.com/ |
| HubSpot | 75,306 | https://www.hubspot.com |
| OneSignal | 23,135 | https://onesignal.com |
| Constant Contact | 15,173 | https://www.constantcontact.com |
| HighLevel | 14,759 | https://www.gohighlevel.com |
| ActiveCampaign | 9,726 | https://www.activecampaign.com |
| MailerLite | 5,183 | https://www.mailerlite.com |
| RD Station | 4,690 | https://rdstation.com.br |
| Poptin | 4,553 | https://www.poptin.com |
| Sendinblue | 3,898 | https://www.sendinblue.com |
| Campaign Monitor | 3,425 | https://www.campaignmonitor.com |
| OptinMonster | 3,418 | https://optinmonster.com |
| ConvertKit | 3,025 | https://convertkit.com |
| Tolstoy | 2,006 | https://www.gotolstoy.com |
| Birdeye | 1,931 | https://birdeye.com |
| 6sense | 1,390 | https://6sense.com |
| SendPulse | 1,300 | https://sendpulse.com |
| ManyChat | 1,253 | https://manychat.com/ |
| Dreamdata | 1,140 | https://dreamdata.io |