Thunderbird is a free, open source email client from the Mozilla community that supports multiple accounts, calendars, contacts, add-ons and strong spam and privacy protections.
Mozilla is a non-profit-led open source community that develops the Firefox browser and Thunderbird email client and campaigns for an open, accessible and privacy-respecting internet.
Pipedrive is a CRM platform originally from Estonia, designed for sales teams, offering visual pipelines, email, automation and reporting to manage leads and close deals.
Zoho is an Indian software company offering a broad suite of cloud business apps, including CRM, accounting, email, project management and HR tools for small and mid-sized businesses.