About to wipe my iMac and set it up as new

Question… my iMac is starting to show signs fo being full of cruft… I am seriously considering wiping it and reinstalling macOS and starting over… lots of conflicting within myself as I ponder this move… any thoughts about how to keep what’s important? I got my first Mac in 2009, and have never done a clean install of anything… when I upgrade, I use either a Time Machine backup or a CCC backup from which I restore… so I have almost 10 years of crap carried forward…

The basics I get:

• Make a current backup (or two)
• I have access to all non-MAS software, including registration keys
• iCloud will restore Keychain, Contacts, Calendar, etc

I also have questions...

• How can I get my old email back on my newly set up iMac? If I export all mailboxes, will that work? What about any email attachments?
• Can I still access old TimeMachine backups if I create a new account? Will I get locked out because I am not the same "me" that created the backups?

Has anyone here done such a thing? Is it worthwhile? What issues can I expect to arise?

 

Thanks... I did export my mail and then imported it... I was worried about the mail rules, but they magically showed up... I have one gmail account that I wanted to add as POP, but HS mail doesn't seem to allow it any more (GRRRR).

I did not want to do the migrate because of nearly 10 years of cruft... I think I have it sorted out...

 

One last concern before I do the deed... what happens to over 4 years if TM backups? Will I be able to access them, should the need arise? Or will macOS recognize me as someone else (that is, as a different user than the one who created and owned the backups) and deny access?

 

Perhaps...

 

Just a follow up... for the most part, the deed is done... I do not have access to my TM backups (was hopeful, but not the end of the world)... my system is much cleaner and leaner... still finding little missing stuff like user fonts, keyboard shortcuts, etc... will take a few days to sort most of it out, but overall, it's a huge improvement over where I was...

 

I got my first Mac nearly ten years ago. Over the ensuing years, I upgraded machines several times, and always just moved my stuff onto the new machine by restoring from at TM backup. As time passed, I managed to encounter bugs and issues that gradually caused some of the features (like continuity for phone calls and intermittent issues connecting to network devices like NAS and printers) to not work properly. I also began to experience issues with account permissions...

Apple suggested creating a new account on my current Mac and reconfiguring everything in the new account, but that also caused issues with some software, as I installed it for my original account only, meaning that I had to reinstall a lot of stuff for "all users"... also, my Open With context menu from within Finder was corrupted - sometimes it worked, but mostly it took forever to populate, and when it did, there were programs listed that had long been "uninstalled" (pretty much a misnomer, as 'uninstalling' software is much like trying to clean up a paint spill in shag carpeting).

FWIW, while there aren't .DLL files being left behind as with Windows, there are still plenty of files left behind in the Library folder, containers, .plist files and the like... so there was cruft, which I define as trash, debris, or other unwanted matter that accumulates over time.

And after spending a couple of days preparing everything, and another doing the install, all is right with my Mac again.