| MailChimp | 107,764 | https://mailchimp.com |
| Klaviyo | 82,147 | https://www.klaviyo.com/ |
| HubSpot | 75,724 | https://www.hubspot.com |
| OneSignal | 23,686 | https://onesignal.com |
| Constant Contact | 15,203 | https://www.constantcontact.com |
| HighLevel | 14,848 | https://www.gohighlevel.com |
| ActiveCampaign | 9,793 | https://www.activecampaign.com |
| MailerLite | 5,229 | https://www.mailerlite.com |
| RD Station | 4,756 | https://rdstation.com.br |
| Poptin | 4,601 | https://www.poptin.com |
| Sendinblue | 3,939 | https://www.sendinblue.com |
| Campaign Monitor | 3,443 | https://www.campaignmonitor.com |
| OptinMonster | 3,442 | https://optinmonster.com |
| ConvertKit | 3,031 | https://convertkit.com |
| Tolstoy | 2,035 | https://www.gotolstoy.com |
| Birdeye | 1,938 | https://birdeye.com |
| 6sense | 1,391 | https://6sense.com |
| SendPulse | 1,317 | https://sendpulse.com |
| ManyChat | 1,261 | https://manychat.com/ |
| Dreamdata | 1,142 | https://dreamdata.io |