There use to be a zaptwo here but their policy has changed...
Here Resides AstalaMail.

AstalaMail.
The, Webmail Client plugin

Aimed at accessing mail provider's native web clients to enable lifecycle support for different providers, in one app with a tailored UI.
Multi Account Support and more. Support planned for ANY account, ANY host/service/app.
(ex: can be used as an anonymous multi-mail client when in combination with guerillamail)

Once destined to be a stock Moonala plugin, it is now becoming its own, while retaining full compatibility with Moonala. Only need a webmail client? Install it alone for less than 1.5MB.
Currently in public testing only, not even in Alpha.
Full Release Planned for 2027, Potentially Accelerated to 2026 With Your Help.