I have googled this and there have been already lots of people facing this same issue; but after trying the various suggested methods nothing changes and I just wanted to give it one last shot and see if anyone can take a look at my specifics and help me fix it.
I receive emails flawlessly on the mail app, but cannot send them without receiving this message: Cannot send message using the server stmp.atlas.cz:firstname.lastname@example.org
I suspect it may have to go with the foreign (Czech) email server? Anyway, here's the setup.
If anyone has any suggestions I'd appreciate it so much. If this is just because my email server is too obscure that's alright, it's not too big a deal, I'm still receiving emails through the app and that's more important.