For my customer's e-mails, I require the option for them to select various products while subscribing to a newsletter through this e-mail service. The database of tinyemail supports this through "tags". I requested support to add the ability to select tags in a subscription form. They replied within hours, saying they were adding it as a top priority to their to-do list. That impressed me a lot and I hope for the integration soon, so I can get started to invite customers.