I need email marketing for...

That's the first question you should ask yourself before going into email marketing in your company. The easy answer is “Because that's an additional channel for user retention and selling our products”. And that statement got some point, but not so simple, my friend. Emails in the first place are great for delivering information to your clients. Any type of information, not only screamy selling offers. Emails, which your users receive from you should stick to your tone of voice, your culture of communication, style and the essence of your company.

All your emails should represent your company, that means that your client should detect your company in your every email, doesn't matter whether it's promotional offer, message about password change or happy birthday email. And that's where such things as company style, tone of voice, etc. will come in handy. 

As you have already figured out your email marketing strategy should fit to your business model and segment. Email strategy for a small start-up and a large company differs a lot! First of all, the startups usually don't have such amount of content to get their customers interested in reading all the emails. Just admit it and DO WHAT YOU CAN. Don't push the idea of the detailed email marketing strategy if you don't need it. Start with the small: make welcome email, send weekly/monthly digest on how your product is growing and getting better for the customers. Make the start simple so you could get more sophisticated with time. Perform organic growth of your email marketing through a lot of testing and polishing your emails.

So what information you need to provide to your clients in your first emails: tell about your product, what users can expect from it, what activities or interactions they can perform to fill their needs. Mention your main advantages, ”killer features”, Performance and Delighters, if you use Kano model. Also it is a good practice to guide your client through the process of activation in your first email. Tell them what they need to do to use your product in full power. That's the perfect start of your email marketing from the client's point of view. It passes the message ”We care about your comfort with our product” to the client. 

Summing-up: only useful information for the user in your first ”Welcome” email. Don't try to put all your ”Done” column from the task tracker. I'm sure it will be a longread email, but just don't do it. Start with the small email marketing strategy to gain more organic weight with time.

What next: How to properly collect your subscribers list and why it is not the same as “user base”.