The standard email attribute type URI for the AX extension is "http://axschema.org/contact/email". However, many of the OpenId providers do not support this standard attribute type URI but instead support one of the following:

• http://schema.openid.net/contact/email
• http://openid.net/schema/contact/email

The Jenkins openid-plugin currently supports only "http://schema.openid.net/contact/email". For a better user experience, it is recommended to ask/support for all three email attributes.