More startup snags

IS THERE A WAY TO CHECK MY MAC FOR HARDWARE PROBLEMS?

Hardware faults are relatively rare, but if you can’t find the cause of a problem elsewhere, use the built-in Apple Diagnostics. First shut the Mac down (don’t just put it to sleep) and disconnect everything except power, keyboard, mouse, display and internet. Turn it on and immediately hold the D key until you’re asked to choose a language. Apple Diagnostics then takes a couple of minutes to do its work, and lets you know the verdict.

HOW CAN I REPAIR ERRORS ON MY STARTUP DRIVE, SINCE DISK UTILITY CAN’T?

It can’t carry out repairs on the drive you’re running macOS from, so start up from Recovery and select Disk Utility. You can now look at your startup drive. If it can’t be repaired, restore it to an empty drive, or restore from your Time Machine backup.

I HAD TO REFORMAT MY MAC’S BUILT-IN DRIVE. NOW WHAT DO I DO?

Start up from Recovery (or Internet Recovery). Then, if you have an up-to-date Time Machine backup, restore from that. If you have your work backed up somewhere else, opt to reinstall macOS, then you’ll need to copy it all back over.

The Mail app can handle all types of email account, but turning on Mail in iCloud’s settings (in System Preferences on the Mac or Settings on iOS) only activates your iCloud address. Add others (Gmail, your ISP email, etc) in Mail > Add Account in Mail on macOS or Settings > Passwords & Accounts > Add Account in iOS.