This appears a MVP, I think it looks quite nice at this stage and it seems to be an easy API to utilize. So the product side looks great for a MVP, if you are

This appears a MVP, I think it looks quite nice at this stage and it seems to be an easy API to utilize. So the product side looks great for a MVP, if you are lacking anything at this point it is the information about your company, I suppose trust is involved since 1) I am giving you access to my communications and 2) I expect my letters to reach their destination. If you take anything away from these HN comments, I think you should create dialog with your customers. Tell them about your service. Tell them what makes it safe. Tell them what makes you trust worthy. Tell them about your technology.