Some places don’t allow it. I tried to buy a monitor from Dell.com a few months ago and they silently canceled my order. I called support and they said their system doesn’t allow + addresses and asked me to use my main email. I told them bodilessgaze+fuckdell@gmail.com IS my main email.
You can sign up as youremail+whatever@gmail.com and all emails still go to youremail@gmail.com. Other services will usually treat it as a different address and let you make new accounts.
Some places don’t allow it. I tried to buy a monitor from Dell.com a few months ago and they silently canceled my order. I called support and they said their system doesn’t allow + addresses and asked me to use my main email. I told them bodilessgaze+fuckdell@gmail.com IS my main email.