I have registered using github before, and I’d like to sign in using BitBucket. I am using the same email address in Github and BitBucket.
Today I tried to sign in using BitBucket, but after I input my email address, I was told it was used already.
I guess in your system, email address must be unique. But I think probably you need to consider the third part id as well.
Please tell me how to login using bitbucket.