I wanted to implement an email protocol different from POP/IMAP/SMTP, for 3rd Edition, starting from MR.

As suggested i looked into Nokia MTM docs and TextMTM example (also the latest version 1.1); but i need some clarifications.

I see that the TextMTM implements all the components and a TextMTM mailbox is created, but TextMTM is not recognized as a mail type... in fact it doesn't appear as a protocol choice when i create a mail account. Is this possible only on Eseries devices or should i look into some particular API?
In the example, to use TextMTM the user has to choose TextMTM and not E-mail... this could be not very clear for my end-users...

If this is feasible, could it be a solution to the heavy capabilities requirements? I'd like to implement only the e-mail protocol (the equivalent of POP/IMAP), so maybe i could implement only the server MTM part that doesn't requires All-TCB... ?

Thank you in advance for clarifications/starting points