I recently upgraded my Wildblue to the unlimited data plan. Since that time, I have not been able to send any emails to anyone with an aol.com email address. Many of my clients and colleagues use this and it is a BIG problem. I've tried sending from different computers, different ISPs, and even my phone. The only common thing is the email server. Is this a known issue, and if so what is the workaround?
Your problem seems to be an AOL problem. Since you tried with other ISP's that rules out Viasat as the cause. Perhaps you need to look up technical support at AOL and inquire what they can do to open their servers to your account.
Just one suggestion... Sometimes a company will have an authorization system that remembers the computer you access your account from. If you try to use another computer it won't allow it until you verify that computer is authorized to access the account. In this case they usually have a way to contact you (phone call or text) as a way to verify it is actually you attempting to access the account from a new device. If this is the case, be very careful about deleting cookies in your devices as that is the method of choice to check for a device's authorization to access that account.
Again, use a Gmail or Yahoo email account and your issues will be solved.