- ODSNet
- Olark Live Chat
- OnePageCRM
- OpenCart Mailchimp Integration Pro
- OpenTable
- Opinion Stage
- OptinMonster
- OroCRM Mailchimp Integration
- osCommerce
- Outfunnel
- Outgrow
- Oviond
- Paperform
- PassKit
- PayWhirl Recurring Payments
- Personalized Triggered Emails
- Personizely
- Philantro
- Pipedrive
- Planning Center
- Playable | Instant-Play Video in Email
- Plug-in to SMS with Mailchimp
- Pluga
- Poptin - Smart Popups & Forms
- Postcards — No Code Email Template Builder
- PrestaShop
- Privy
- Product Recommendations - Barilliance
- Prospect CRM
- QuickBooks Online
- QuickTapSurvey
- Quotient
- RallyBound
- Recurly
- ReferralCandy for Mailchimp
- ReferralHero
- Reportei
- Responsly - Beautiful Surveys for Mailchimp
- Resurva
- Retention.com
- Rewards Fuel Contests
- Rewind Backups for Mailchimp
- RightMessage
- RoboAuditor
- Rocketspark
- Salesforce Integration by Beaufort 12
- Salla
- SamCart
- Save time with Mailchimp and QuickBooks
- Scoop.it Curated Newsletters
- Send Images to RSS
- SeoTools for Excel
- ShipStation
- ShopKeep
- Shoplazza
- Shoprenter
- Shopware
- Show by Animaker
- Simplebooklet
- SimpleTexting
- SimpleTix
- Skyvia
- Slack
- SlickText SMS Marketing & Mass Text Messaging
- Smile.io
- Snapchat Lead Generation
- SparkLoop
- Springbaud For The Raiser's Edge
- Square
