django celery used in asynchronous send mail problem

　　For a long time but could not find by prompting the need to explain Celery 4.x or later version Django1.11, but using version django1.8.2, the first thought is what myself something goes wrong, to find them.

　　Yes start the task queue task processing starts no problem, open the input address on the error.

　　Eventually see using Celery4.3.0, then changed to version 4.1.1 is ready for use.

　　Specific questions not found, should be the new version added some stuff, and then later study.