Sort of. Netscape Communicator critically never included server infrastructure and was completely focused on e.g. connecting to your ISP's email servers.

Although a great 'client' experience is absolutely crucial for Firefox Premium's success and would be a modern resurrection of Netscape Communicator in that sense, what I mostly need is convenient 'servers' from a company that I can trust and a business model I can support. In a sense that would be a modern way of meeting the needs of Netscape Communicator, sure :)

Agreed, in this day and age we mostly don't have or use the ISP services that come with our connections.

Would you then use a Mozilla run mail service similar to gmail complete with calendaring and document storage, all built into a suite of client apps ?

I think for a certain demographic this could turn into a good Google competitor if done right.

Doesn't need to be a move back to Mozilla Suit (today named Seamonkey). They can offer web-services for this (just cooperate with an existing Provider like fastmail), but with trusted privacy features and embedded in the browser with first class-quality-extensions.

Or they push thunderbird, the mail-client they brought into the world to just ignore it for such a long time. A trustable privacy-first mail-client with brainless configuration and maybe some useful modern PIM-features would sell well enough to satisfy a price. I mean there are already services doing that, mozilla couild cooperate with them or just push their own weight in the ring.