I can’t understand how anyone could think it was acceptable for any *unix to be installed without a working MTA in the first instance, or for the process of getting one working to be so opaque and poorly documented in the second. Pushing back on the OP for such a reasonable request just seems unkind, especially a non-native-English-speaking OP. FWIW, I agree with everything OP says 100%.
So, to make things simpler for the next person who finds themselves on this page after entering “manjaro mta” into a search engine, here’s what OP’s frustrated persistence revealed as the recipe for success:
I am glad his post is visible there like this, though his post can be helpful also in my topic. Especially his commands should be visible in the first post of my topic to save people time. But no, you do not want this. Moreover your forum attempt to waste more time by not allowing me to update my posts in that topic to post updated useful information. I think that editing my own post usually means no hurt.
Please delete this if you have ended reading to this point, and thank you for your help in my topics. I appreciate it.