This sentence doesn't quite parse starting at the "to one of the .. getting help" clause.  Maybe you can just drop that since the sentence is already a bit complex and the email options are fully discussed in the contribute page mentioned below.  Perhaps in the `Getting help` section there could be one more sentence like `Finally, you can send a private email to the astropy core developers at astropy-feedback@googlegroups.com.`  This would increase the visibility of this option.