Marketplaces and Classified Ads
In short. A selling address outlives the sale by years and ends up in lists you never agreed to. This is one of the few situations where a throwaway address fits almost perfectly, provided you keep it separate from your marketplace account.
What happens to a seller's address
You list a sofa. Four people write, one buys it, the sofa leaves. Your address now exists in four strangers' mailboxes permanently, and on many classified sites it was visible on the listing page itself for anyone to collect.
Collection is automated. Scrapers walk listing sites continuously, harvesting contact details into databases that get resold. The address you used for one piece of furniture becomes an entry in a list of "verified active sellers", which is worth more than a random address and gets traded accordingly.
The spam that follows is not the ordinary kind. It is aimed at people who have demonstrably sold something, which makes it more specific and more convincing.
What arrives, and what it is trying to do
Three patterns show up again and again in seller mailboxes.
The fake delivery service. A message claiming the buyer has paid through a courier's protected payment service, with a link to "confirm receipt" or "enter your card to receive funds". The site behind the link is a copy of a real courier's page. Money moves out, not in.
The fake payment notification. A message that looks like it comes from the marketplace, telling you the payment is held pending your confirmation. Same mechanism, different costume.
The verification link. No money mentioned at all. Just a request to confirm your listing, your account or your identity, leading to a login page that harvests your marketplace credentials. This one works because it asks for something plausible.
All three fall apart under a look at where the message actually came from, which takes about ten seconds and shows that it never passed through the courier or the marketplace it claims. All three also depend on reaching you by email, so all three become considerably harder if the address they reached you at stops existing when the sale does.
Why this scenario suits a throwaway address
Most bad outcomes with disposable addresses come from using one where recovery matters later. A private sale is the rare case where later genuinely does not exist: the deal closes in days, the item leaves, and nothing about it needs to be reachable next year.
The timing also fits. A guest mailbox here lives twenty four hours from last use, which suits a fast sale. A free account extends it to seven days from your last sign in, which covers the usual negotiation. Anything longer than that is a sign the deal needs a different channel anyway.
Where it will hurt you
Warranty and returns. If you are the buyer and the item fails, the correspondence proving what was promised sits in a mailbox that no longer exists.
Disputes. Marketplace arbitration asks both sides for evidence. The messages are the evidence.
The buyer coming back. People who bought one thing and want another are the easiest sale you will ever make, and they cannot reach you.
Anything shipped. Tracking, delivery notices and courier problems all arrive by mail, and courier problems are exactly when you need the notice.
Two different addresses, not one
This is the part most people get wrong.
The account address is your identity on the platform. It holds your rating, your history, your payouts and your ability to recover the login. It must be permanent. Using a throwaway address here means losing the account and every review you earned the first time you forget the password.
The listing address is contact for one item. It can and should be temporary, because its whole job ends when the item does. It is the second of the four things people mean by a burner: an address that has to survive a conversation rather than a single code.
Many classified sites let you keep the account address private and communicate through a relay or a per-listing address, which does the same job. Where they do not, using a disposable address for the listing and a permanent one for the account gives you the same separation by hand.
Close it, do not wait it out
When the item is gone, delete the address rather than letting it expire on its own schedule.
The difference matters more than it sounds. An address that is still alive for another twenty hours is still collecting the scraped-list traffic and still usable by anyone who saved it. Asking for a new address here deletes the previous one immediately, so the gap between "sold" and "unreachable" is one click rather than a day.
Copy out anything you still need first. Deletion is immediate and nothing is recoverable.
If you are the buyer
The same address goes to a stranger, with one difference: you usually want the seller to be able to reach you until the item is in your hands.
So the buyer's timing is longer than the seller's. Wait until the item arrives and any return window has closed, then discard the address. If the item is expensive enough that a dispute is plausible, use an alias instead, which you can switch off later without losing the correspondence.
And be careful about which address you give a seller who is pressing for one. Sellers who move the conversation off the platform immediately, before any details are agreed, are following a script, and the first step of that script is getting you somewhere the platform cannot see.
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