It appears that some of the major email providers have some special rules or communication protocols that are not standard now.
MSN, Hotmail, AOL, Google and some others. It appears since they are so big that they make their own rules. I doubled checked and our system meats and surpasses all standard and legal requirements for spam and communication protocols. This means we now must build in support for their special little demands so our users emails do not end up in their spam or 'black hole' boxes.
They are going out side accepted standards and causing clean, non-abusive emails to be blocked. We are not on any blocked spam lists and have strict spam policies and a system in place using all the major block spam lists. We do not enforce anything that is not a universal acceptable standard but those companies are.
We are looking over how we will handle this. Quite frankly, we have no choice but to build in the special case support they may force since so many use their free email services. The problem is each one of them are requiring a unique set of protocols and non of them agree on a set standard. Totally ridiculous.
We may have to enforce that our customers not use a free email service on their primary contact email with us or even the paid versions of the above mentioned email providers for the time being.
Rest assured I am personally working on new email rules and protocols in our extensive email spam server that would take care of the problems with some of these email providers. I already satisfied something Comcast was blocking emails for.
Just remember that we and you, our users, have not been a source of spam and we have a strong spam fighting system actively working. These other email providers are not just blocking us and our servers but many many other providers for the fact that they are using non-standard practices to try and curtail spam abuse on their systems. A noble cause with a not so noble effect.
So please make sure that you update your primary contact email you have on file with us to one not associated with the above mentioned problem email providers. Comcast users should be good to go. Please open a support ticket if you suspect any issues between your email provider and tweakedhosting. Most ISP providers do not have these problems but you never know. The main culprits are BIG free email providers, who happen to host the largest base of abusers and spammers who use free systems to spread spam.
--update--- reverse DNS, SPF records and domain keys are supported in our system, this helps with Comcast, Gmail (Google) and Yahoo - you may need to ask for some measure to be applied per Cpanel account level if you are having issues still.