Since February 1st I could not access a site that I have been a member of for over a year. It would time out, saying the site could not be reached. I tried Chrome, Firefox and Safari browsers with the same results, and I also tried two different devices. I notified their tech support by email, and he asked me for my IP address so he could check it out. The next day he replied and asked me if I had a shared IP address. He said my IP address was on a global greylist, and that sometimes that indicated that someone, perhaps a scammer was sharing my IP address to access sites. He showed a screen capture that showed my IP had attempted to access their site 380 times in a very short time frame. My ISP assigns me a dynamic IP, so I turned off and unplugged my router for about 15 minutes. When I reconnected I had a new IP address and was able to access the website with no problem. I had never heard of something like this, so I thought I would mention it here to see if anyone else has had this problem.

Unfortunately this is not unusual. And it is very common with email.

Many email servers check not only the IP address of the sending server but also the IP address of the sending device.

And those IP addresses are compared to blacklists.

I had it often that some receiving mail servers didn't accept out emails because our IP addresses were blacklisted.

And they were blacklisted not because we misused them but because many IP addresses from many ISPs in Thailand are misused all the time. So there is a high chance that the IP address which we use is already on one or more blacklists.

 

It's up to the receiving server administrator how serious they take this. It they block any traffic from a "bad" IP address then they block a lot of traffic - including a lot of traffic from Thailand.

Yes I often get blacklisted from my UK (BT) email server  because the IP address I'm assigned by ToT internet provider has been put into the https://www.spamhaus.org/ list of bad addresses.????