Another site is Pookmail.com
This is a 24 hr perishable mailbox. HiLF, I use the same sites as you do, looking for used cars etc. If you use your own address you will be spammed for ever more.
Use Pookmail and the automatic systems will keep pouring the rubbish into your account for days even. You can reply from the Pookmail account although you cannot start an email thread.
If you look at a simple address, say
[email protected], you will probably find a whole raft of emails for 'roger'. Right now there are 10 such messages. Any Roger can find them. If you want a more discrete address then Roger4321 is empty.
Messages to Roger4321 will disappear after 24 hrs.