You need to install and launch gnome-keyring
see: https://wiki.archlinux.org/index.php/GNOME/Keyring

What if I want to be without a keyring?

Since evolution is tightly intergrated to Gnome you'll just have to live with entering your password as evolution have no other option for storing it.

freemor

But that is what I did - I input my password, the mail doesn't fetch.

I can not reproduce the non fetching behaviour.
once I enter my password if fetches fine
run evolution from a terminal. Provide relevent debugging info here. (not everything.. just the bits related to failing to fetch mail)

freemor

Try this:

1. Set auto fetching to 10 minutes.
2. Leave Evolution running for 30 minutes or more.
3. Go back and try to input your password in the prompt that is displayed.

This resulted in no mail fetched for me, I had to click "send / receive" to force it and work around the bug.

But send/receive worked? It sounds like you just didn't wait for Evolution to hit the next 10 minute mark.
Since the PW prompt was probably for an old timed out fetch attempt. You probably just need to wait for the next fetch.

This is starting to sound very much not a bug.

freemor

Would a user figure all that out you think?

With minimal effort and attention, yes.
Re: fetching. Simply waiting a bit after entering the PW would show that you were between fetches
Re: gnome-keyring
- running in a term shows a clear missing 'org.freedesktop.secrets' service
- seraching that = it needs gnome-keyring.
- searching that = how to install and set-up

this issue appears to be very similar to #1932