Hi gsreenivas,
I hope you end up seeing this.
I feel like am your target user for this product. I want to be able to isolate the majority of my data away from these large corporations (namely Google), email is probably the hardest one for me to do myself. I really want to use your product.
BUT, and this is a HUGE but, I am a web developer and I have like 15 domain names. Some from old businesses, some for just random stuff. I accept email from all of them and have online accounts tied to many of them. In order for me to use this product, I absolutely need to bring ALL my domain names with me.
In fact, the number of supported domain names is the primary feature I look at when comparing email providers. If it doesn't support the amount that I have, I immediately disregard it, doesn't matter what else they be offering.
So please reconsider the number of domain names. I imagine there are lots of users like me.
Best of luck to you and your team!