We already have a [canonical question](http://meta.serverfault.com/q/1986/126632) dealing with [inbox deliverability](https://serverfault.com/q/227242/126632). Your proposed question would likely be closed as a duplicate of it. That said, for our reading audience, new answers for our canonical questions are always welcome.

To avoid this, the question would have to deal with a _very specific_ deliverability issue, not sufficiently covered by the existing canonical, which at this time your proposed question does not.