A disposable email address is one you hand over on purpose knowing you will never see it again. It receives the confirmation you need right now, and when the timer runs out the address stops existing — so the newsletter, the reminder sequence and the eventual data breach all land somewhere that is no longer there.
Unsubscribing is a request. It depends on the sender honouring it, on the list not having been sold already, and on your address not sitting in a backup nobody will ever clean. A disposable address does not negotiate: the mailbox is gone, so there is nothing to deliver to.
It also contains the damage from breaches. An address you used once and discarded is worthless in a credential dump, because it does not exist any more and was never attached to anything else you own.
Every visitor is handed a random address immediately. If you would rather have something you can remember and type into a form by hand, choose your own name and domain with the Choose your own button.
Random addresses are built from a word plus eight random characters, which is enough entropy that nobody is going to stumble onto your inbox by guessing. A custom name you invented is easier to guess by nature — a fair trade for being able to type it, but worth knowing.
Invoices, tickets and PDFs arrive intact and download normally. Formatted mail renders the way the sender designed it, inside an isolated frame with scripts already stripped out, and remote images stay blocked until you click Show images — so the sender never learns that you opened it.
Yes. Choosing which address to give a website is your decision, the same as choosing which phone number to list. Some sites do refuse disposable domains in their terms — check theirs if it matters to you.
Only while it is alive. Once the timer runs out the name is released and anyone can claim it, so never use one of these addresses for anything you need to keep access to.
Possibly. Many services keep blocklists of disposable-mail domains. If one address is refused, switch to a different domain from the picker and try again.