It doesn't seem to take very long before Geary stops working. I have one e-mail account on my FLX1s phone, that I use only for things ob my phone - calendar notices & ev charging apps mainly. It will be working then suddenly it starts throwing errors. See attached. Note I rarely/never use it to to send e-mail.
NOTE: at this point Geary is useless. It cannot connect to the gmail.com servers. I have e-mail that it initially downloaded but nothing much after that. And nothing in the last 24 hours. Both the gmail web interface and K 9 mail show new messages since then.
As I reported in an earlier thread around WhatsApp, Geary seems too embedded in the device to be removed. However, absent a fix for it, it seems to just be occupying space.
The dual-nature of the FLX1s comes into play here. Geary operates in the Linux realm while I installed the K9 Android app. For receiving mail, K9 works but when I tried to send my contacts.vcf to myself for import into Nextcloud, it can't find it because it's in the Linux realm. Geary could find it if it was actually operational. A direct replacement for Geary means an e-mail client for Linux.
I don't send e-mail from my phone very often so I probably don't need anything more than K9, but it would be nice if Geary worked.