His old laptop did something similar with outgoing email taking a while to initiate sending or for new email to get fetched and they thought a new computer would fix it. Once the sync completes, outgoing mail sends and incoming mail comes in, but then it will sync again and no mail transfers until it's done. I've set the sync interval to 1 minute or 5 minutes or 30 minutes. I've tried unsubscribing to all the folders but the Inbox. I'm pretty familiar with the way Outlook and Gmail work and have had problems with it in the past as many people do (as evidenced by all the problem posts found on Google).
Sometimes it starts over and sometimes it goes up to 8 minutes. The problem is that in the status box, it shows synchronizing subscribed folders and usually shows about 2 minutes. I'm familiar with all the basics like turning on IMAP in Gmail (which was already on since he's been using the account already with his old computer and Outlook). I set up a new computer with Outlook 2016/2019 and connect to his existing account in IMAP mode. I have a client using regular email accounts.
