…this is really crazy: I find dozens of users with the same problem:

[https://community.swisscom.ch/t5/E-Mail/Mailversand-funktionier-nicht-mehr-Blacklisted-IP-xxx-xxx-xxx/td-p/551802](https://community.swisscom. ch/t5/E-Mail/Mail-sending-no-longer-works-Blacklisted-IP-xxx-xxx-xxx/td-p/551802)

@DonPedro66

I sent you a PM.

Greeting

Chris

…So, emails are all working again 😀…I had to deal with two lovely people from Swisscom yesterday who really took care of my concerns -> Thank you very much! I “flattened” all of my 3 PCs and reinstalled them. Now I hope it lasts…. Thank you for your good advice 👍

Great, it’s working again now.

Ultimately, what was the problem?

@DonPedro66

How long it works depends largely on the behavior of the user. Because the behavior of the user is even more important than technical protection against viruses and Trojans.

This statement is only partially true. I am and have always been extremely careful. I only ever open emails from trustworthy senders. I’ve never wandered around on indecisive pages. I’ve never downloaded any tools or software from the internet. And yet I was repeatedly banned for over six months. And I even let Swisscom support seduce me into clicking on links or tools in their emails. Swisscom will not be spared either. People are forced to pay electronic invoices, even though many have already been hacked with fake emails from alleged Swisscom. That’s why I still demand paper technology. It’s really not always the user. Technical defects and constant changes by providers are often responsible. Often you are used as a test subject as a final round so that you can save on development costs.

@hed this may be especially the case in companies with many employees. I am extremely careful when dealing with PW. I suspect that the malware crept in when installing a software update or something similar.

@kaetho…I can’t even answer that for you exactly. Apparently “spam emails” were constantly being sent from my IP address (and my email address), even after changing the passwords. Ultimately, only Swisscom itself (the “Malware” team) could do anything. Maybe someone from Swisscom can describe it in more detail…

@DonPedro66

It’s hard to say how you caught it. There are malware, worms, viruses, etc. or also Exploit (vulnerabilities in programs) the things on your device do things that you don’t know or can’t know because, like me, you simply don’t have the know-how.

Getting on the Internet, no matter which site, is a danger in itself. I wouldn’t put my hand in the fire for any side or program.

@vormirdieSinflut You already have an operating system that is updated daily or weekly. This is done not only to improve something but also to close newly discovered loopholes. You also have browsers, add-ons, etc. on your PC that hide unknown dangers. So I can’t imagine that your PC or device only has one OS and one browser, that’s rather unrealistic. Caution is definitely a good way to go.

Greeting

Chris

@DonPedro66 and @ChristianG

Thanks for the info. I’m asking because I’d be interested to know exactly what you caught there, but more importantly how Swisscom ultimately took action against it. Are there actually situations in which you can no longer make any progress yourself?

Today, a PC with Windows 10, a Microsoft account and normal internet integration can be completely reinstalled very quickly, without any data loss.

Would a courageous complete reinstallation of the PC have helped here?

@kaetho

Reinstalling Windows 10 is not as easy as reinstalling an iMAC.

With Windows 10 it’s quick if you have a subscription to Office 365, but as soon as you have installed full versions of Acrobat Adobe, Teamviewer and many additional purchased programs, things get complicated if licenses are available.

With the MAC you can always create a 1 to 1 copy of the system after the initial installation and then use it immediately without purchasing additional backup programs.

@vormirdieSinflut

The mail program is the symptom, so to speak, the illness or the intrusion into your network does not occur via the mail program but via a weak point in the home network, whether the operating system, utility program, user program, NAS, etc. can no longer be traced.

Companies set up DMZs to prevent or minimize things like this:

[DMZ (Computer Science)](https://de.wikipedia.org/wiki/Demilitarized_Zone_(Computer Science))

Greeting

Chris

@kaetho

Swisscom blocks the Anschluss to protect the customer. If the customer needs our help, a Malware Team (free) or MyService (paid) are available. The customer is also free to hire an external IT expert.

So far I have not come across a case where no solution was found. Sure, searching, finding and eliminating is time-consuming and certain pests are stubborn. Setting up new devices also takes a lot of time and setting up the backup including network elements again is also time-consuming.

You assume that the malware causing the problem is on a PC. I really mean resetting everything in the home network as well as current FW for network printers, IoT, updating programs/utilities (exploit), etc. simply everything that is connected to the home network and can communicate externally.

A DMZ would also be a way to prevent or minimize this:

[DMZ (Computer Science)](https://de.wikipedia.org/wiki/Demilitarized_Zone_(Computer Science))

Greeting

Chris

@ChristianG

It is becoming increasingly difficult to defend yourself against such attacks when you see that even hospitals, federal companies, companies, transport companies, etc. are being hacked and they certainly have better protection than private individuals.

You should also not underestimate Smart Home accessories which can be used as a gateway.

@WalterB Windows vs. Mac, that was once. Today, what you think works for Mac can also be done with Windows.

@ChristianG yes, I assume that the problems come from the PC. Luckily I haven’t experienced anything else yet.

What exactly was the problem in this case, and how was it solved if it wasn’t the PC?

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@ChristianG wrote:

[…] A DMZ would also be a way to prevent or minimize this:

[DMZ (Computer Science)](https://de.wikipedia.org/wiki/Demilitarized_Zone_(Computer Science))

Basically you are absolutely right.

However, it should be noted that there is a function available in the Internet Box’s setting options that is also called “DMZ”, but has the opposite effect in terms of security. Not that forum participants still have the idea that they would improve the security of their webcam, for example, by putting it in the Internetbox DMZ…

We have been experiencing exactly the same situation for weeks. Even after purchasing a security subscription, Swisscom cannot help. The only solution is…that we should take every device offline for 3 days in order to apparently recognize which device should generate this block.

For me it’s inexplicable and by no means solution-oriented. And I’ve been a Swisscom customer since I was a child and pay a hefty monthly fee…

It is clearly incompetence on Swisscom’s part.

My domain was also blocked yesterday. Behind the domain there are only 3 pure HTML pages and CSS.
No script, no tool, nothing executable, nothing like that.

Apart from the fact that the domain, the website is easily accessible on other networks. Only Swisscom is bucking.

Not for the first time, it should be noted. Even when there was no, zero data behind the domain. I didn’t know that nothing (no data) could be so dangerous for Swisscom.

Maybe because the domain is not hosted on Swisscom?

I’m so annoyed!

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@Loneissik87 wrote:

….The only solution is….that we should take every device offline for 3 days in order to apparently recognize which device should generate this block.

Inexplicable to me and by no means solution-oriented.

This approach is exactly solution-oriented…