It's not gmail specific, it's standardized as a "sub-address" and not part of the username of the email. smtp has worked like this since the 90s at least.
Do you have a cite for this? AFAIK "plus addressing" always been an optional implementation done by certain email providers themselves, but wasn't an actual part of the standards.
Comments
It's not gmail specific, it's standardized as a "sub-address" and not part of the username of the email. smtp has worked like this since the 90s at least.
Do you have a cite for this? AFAIK "plus addressing" always been an optional implementation done by certain email providers themselves, but wasn't an actual part of the standards.