The top 5 email marketing platforms based on the research I did, except for the Mailchimp which my colleague had used.

1. Mailchimp: Known for its user-friendly interface, Mailchimp offers a range of features including email templates, automation, and analytics.

2. Constant Contact: A popular choice for small businesses, Constant Contact provides easy-to-use templates, contact management, and marketing automation.

3. Campaign Monitor: This platform offers customizable email templates, advanced automation, and robust analytics to help businesses optimize their email marketing campaigns.

4. GetResponse: GetResponse combines email marketing with landing pages, marketing automation, and webinar hosting, making it a versatile option for businesses of all sizes.

5. AWeber: AWeber provides a comprehensive set of email marketing tools, including drag-and-drop email builders, automation, and integrations with other platforms.

Please note that the email marketing landscape is constantly evolving, and there may be newer or more advanced platforms available since my knowledge cutoff in September 2021. It’s always a good idea to research and compare different platforms based on your specific needs and requirements.