We have posted many times here in different areas about the spreading practice by Internet Service Providers handling email to install spam filtering beyond the reach of their clients.
Spam is insidious, but the cure has proven worse than the disease. Now it has reached the point that this 'cure' has rendered the entire email system unreliable.
This is because there is no such thing as a spam filter that works. ALL spam filters catch a percentage of mails that are legitimate, even important, while missing much of the spam they are designed to eliminate.
So, if you email anyone, be sure the intended receiver has another way to contact you because you have no way of knowing if their reply can reach you or if yours will reach them.
Just because you have exchanged email with someone before is no assurance that you will tomorrow. The mails that are blocked change every day.
Only when customers demand that they be in control of what they will be allowed to read will this practice be ended. So, tell your ISP that you demand that all of your mail be available somewhere for you to see, so you can pick out the emails from your spam folder that are important to you.
The reason for this post is that most people do not know they are paying someone to do this to them. After all, you are not likely to know about things you never receive. They will often deny that they are censoring your mail beyond your reach but most now do.
This has become very frustrating for people like me that depend on being able to communicate through email. Now I have to attempt to call everyone that I email just to see if they got it.
Ridiculous.

I can't always do that.
So, if you email me for any reason and do not receive a reply it is not because I didn't sent you one. More likely, you didn't include a phone number or any other method for me to reach you. Dead end. I often do not know that mail was blocked from you either. Try calling me if you didn't receive a reply.
Bottom line... email used to be very reliable, now it is more like a message in a bottle.
Everyone should speak with their $$ and put an end to this abuse.
OK that's my rant for today