I am trying to find out when I bought this computer. I didn’t register with Dell so I am searching gmail. I tried date ranges with yyyy/mo/day and day/month/year with subject Dell, searching all mail including spam. Nothing comes up, but I just do a basic search for Dell I can see a dozen results on the 1st page.
Basic search looks at more than the subject.
Would it be easier to check your credit card statements?
Another option, since you’re talking about a Dell computer. Go to Dell.com/support, enter the service tag (what Dell calls a serial number) on the screen and select Warranty Details. The site will show the ship date for the computer.
You can also go to Settings --> System --> About (bottom of left column, if you’re on Windows 10) and scroll down to Windows Specifications - it lists an “Installed on” date which, for me (since I haven’t ever reinstalled Windows 10) gives me a reasonably close date of when I purchased the computer.