Question: After updating to High Sierra, Mac Mail does not sync
I finished installing High Sierra this morning (it took forever, btw!), and since that time, my Mail app has not synced. I have an iCloud account and 6 Gmail-based accounts that have not received any new mail in over 5 hours. (I've received and deleted plenty of mail using other devices in the meantime.) At the bottom left I see "downloading messages", but there is no sign of life here.
I'm using a 2013 iMac with 2.7 GHz Intel Core i5 and 8 GB of memory.
iMac, iOS 11.1, null