Peter Bloomfield:
That all looks pretty harmless. I've seen similar Gtk-WARNINGS, with no obvious issues. The "No cache..." message is normal for the first time an IMAP folder is used, and "quitting" isn't serious.
I don't see anything that would lead to problems.
Bob Goodwin:
Yes, so I was told by Ed Greshko, it [in Fedora 24] still wasn't receiving but I haven't had time to find what's wrong there, the install didn't go smoothly and I find that once I start "fixing" stuff there are strange problems that happen. If the install works right off then Balsa seems to just work.
It's disconcerting to see a pile of warnings when you run programs from the command line, sometimes they are completely unimportant to you, only of interest to those writing the software, but you have no way of knowing that.
One thing to bear in mind is that, often, software has a variety of options to it as to how it's going to do a task, and you're seeing the options that got discarded.
e.g. If I run mplayer, I get a slew of messages about not being able to use IPv6, an infra-red remote control, and other things. None of which stop it doing what I've asked it to do, at that time. And most of those things, I can identify and not care about.
But when it comes to the things like you saw, you cannot tell if there's a software problem, or it's just reporting things that are unimportant to the program working. Various dbus warning messages do look like error reports, when you see them whiz by.