92

There's specifically a blackhole prefix in IPV6, as described in RFC 6666, it's 100::/64. IP4 does not have an explicit black hole like that, but a non-existent host on one of the reserved blocks would have that effect. (e.g., 240.0.0.0/4 is "reserved for future use" and will not be routed by anything.)


40

There is such a thing as network Black hole. If there are no devices in the network with IP address 192.168.0.10, then this IP address is kind of black hole and it will "discard" all the traffic to it, simply because it does not exist. Protocols which keep track of connection state (TCP) can detect a missing destination host. It will not happen with UDP ...


32

The SMTP protocol does not include any controls over the From: and To: fields in an email. They can be whatever you like, provided you have authority to send emails using the SMTP server. So the short answer is nothing prevents anyone using your domain in emails they send. Even normal users can put whatever email address they like in their email settings. ...


31

The solution to this is not to use Gmail's "forward a copy of incoming mail" feature, but instead to create a filter. Filters are applied to incoming mail before spam detection takes place, giving the option to "never send to spam" in the filter rules. The forwarding filter should use Gmail's "deliveredto:" operator, which handles messages that use plus ...


29

It is to keep the address hidden from simple email scrapers. Spammers sometimes just scan for an email address regex to gather targets for their spam. Doesn't work on more complex email scrapers, but useful to keep some spam out of your inbox.


22

I'd like to say, this does not answer your question directly, but I think you're looking at the problem the wrong way. Do you really want a 400 Watt computer running all day just to screen a couple phone calls? I think Both "what do I do with a Pentium I" and "How do I screen calls" are both excellent questions, but IMHO I think you should split these. Im ...


22

While it isn't a black-hole, you might also want to consider the IPs set aside for test/example purposes (by RFC 5737), especially if your goal is a "safely non-working default" value. 192.0.2.0/24 (TEST-NET-1), 198.51.100.0/24 (TEST-NET-2) 203.0.113.0/24 (TEST-NET-3) Network operators SHOULD add these address blocks to the list of non-routeable address ...


17

There's no "standard blackhole address" as such, nor is there really any requirement for it. You don't say what you're actually trying to achieve, so I can't help you do so, but here are some wrong solutions for your problem that would answer your question as you asked it: You can use an RFC1918 address that's not in use on your network and rely on your ISP ...


9

A direct answer to your question (but not your problem) would be: ps -axjf. That's a and x to see "all" processes (see man page for a more elaborate explanation of these parameters), j for jobs format and f for the fancy ASCII art tree. The ppid (first column) shows the parent process ID. A more direct approach to check the PPid of a specific process would ...


8

While not a direct answer to your question, someone has accomplished something similar to this using a Raspberry Pi. Their full article can be found here but the summary is that they've used a phone to Ethernet adaptor (like the one @Rich Homolka mentions in his answer) wired in to the Pi and a couple of scripts to make sure that the caller is a person or ...


7

According to the docs mentioned by Stefan this is now possible but disabled by default. You can add internal_mail_filter_classes = bounce to your config for bounces to be filtered just as any other mail (including signing filter). This will work well if you only have signing filter. Though you may encounter problems when you have other filters. You should ...


7

This appears to be due to DMARC domain alignment issues. As indicated by the report, the domain for the SPF authentication result was "eu-west-1.amazonses.com", which is non-aligned with the header_from of "mydomain.com". Why DMARC is SPF evaluating with the amazonses.com domain, I don't know. I have the same issue and have not figure out how to resolve it. ...


6

I've got a SOLUTION for Office 365 users. My situation was as follows: web contact form kept being moved to spam tried safe sender, no automatic filtering etc - exactly as the OP did spent 3 hours doing all sorts of tests eventually thinking I was going mad even in the spam filtering area in Office 365 I couldn't find how to disable it for that particular ...


6

If your email client is set up with IMAP, you can uncheck the "Show in IMAP" button on the Gmail Label Settings Page, and it should stop.


6

This is not likely to be the cause of your messages being flagged as phishing/spam. Your <policy_evaluated> elements show that you are passing DKIM and thus you are passing DMARC as a whole. the SPF entry for policy_evaluated has a fail status, however the auth_results list spf as being pass. What can explain the incoherent statuses ? The ...


5

As mentioned in the Messaging app for Windows FAQ: How do I block people from sending me messages? You can't block people from the Messaging app—the app's just a hub that helps you stay in touch with your Messenger and Facebook friends. To delete a Messenger contact or prevent them from reaching you, go to your contact list online and tap or click their ...


5

Depends how ethical the spammer is. There are 3 main results of hitting an unsubscribe option: You will be unsubscribed You will be redirected to a non-existent/useless/malicious site You will be tagged as someone who clicks spam links, and be put on a list that generates more spam From personal experience, I find option 2 happens the most, with option 1 ...


5

At first it was a way to hide the e-mail addres from "robots" that search for e-mail addresses in all possible websites. It was a way to keep the e-mail public (for humans) but hidden (from robots). Quickly ill-intended programmers were able to come around this safety, but still a lot of spam was kept out. The safest way though to make your e-mail public ...


5

Gmail filters do not work on headers but you can use Google Scripts to match the headers against spam text. Here's an example: function myFunction() { var threads = GmailApp.getInboxThreads(); for (var t in threads) { var body = threads[t].getMessages()[0].getRawContent(); if (body.match(/^Header.*?IPAddress/g)) { threads[t].addLabel(label); ...


5

You most likely see spam with the From header set to your own email address because of at least one of these: The domain of your email address does not have a Sender Policy Framework (SPF) record that explicitly specifies which hosts are allowed to sent email on your behalf. Your email receiving server (mail transfer agent or MTA) does not do SPF validation....


4

If you need to access spam messages using pop3, you can create a filter to never place e-mail in the spam folder. According to http://aaron-kelley.net/blog/2008/08/disable-gmail-spam-filter-include-spam-in-pop3-download/ Go to gmail.com Create a new filter Type * in the From field In the next screen, select "Never send it to spam" POP3 now downloads spam ...


4

Sure you can do this. Hook the modem up to the phone line. You will need a terminal program to control the modem. Granted, I havent seen one in years and MS doesnt include one with Windows anymore, but Im sure if you google it, you can find one. You might even be able to pipe the command "ATA" to the COM port in command window. FYI "ATA" is the Hayes ...


4

In a past, evil life I worked on the technical side of the telemarketing industry. I'm sorry. Something that works very well is to quickly stop the caller in their tracks and say, "Please add me to your do-not-call list." By law they have to stop what they're doing and add you to the list. Sometimes they'll ask if you're sure, but that's about it. Just ...


4

I realize this thread is old, but for those who are still wondering: Open the Registry Editor (search for regedit in the start menu), then open HKEY_CLASSES_ROOT\http\shell\open\command Double click on (Default) in the right pane, then delete what is in the "value data" field and replace it with "" then click ok. Then go to HKEY_CLASSES_ROOT\https\shell\...


4

I don’t know whether to call it a missing feature or just a missing option. Luckily you can add e-mail headers to filter on – from the filtering dropdown choose Anpassen… (Customize… for Thunderbird with English UI) at the bottom, and add Reply-To as a new value. Update: as reported in this Bugzilla thread, several versions of Thunderbird have a bug, that ...


4

How can I tell from an email's headers if the sender address is legitimate? Many of these email headers can be (and usually are) forged by spammers when they send their spam. "From:" address Some "Received:" headers can also be forged. SMTP message spoofing shows just how easily this can be done using an open (unsecured) relay mail server. How can I ...


4

Basically they're asking you to add an A record for your NS domain. That means, that if you have ns1.domain.com which is your NS record, it should also have at least an A record with an IP address. You can also add an AAAA (IPv6) address if you have one, as it's used by systems that already handle IPv6.


4

POP3 does not have a concept of "folders" – when you log in, you only have access to one mail store, and that's usually the Inbox. It's really meant to be used in situations where the server does no sorting/filing at all – instead the client periodically picks up all incoming mail and sorts it into folders client-side. If using POP3 is a requirement, see if ...


4

This was done a very long time ago, and predominantly because of your first reason "587 typically employs authentication" and most (not all) ISP's do this. Port 25 has largely been closed down (public do not use / need it anymore) but spammers use to try to hijack port 25 to send out spam. As I noted, this all happened a very long time ago in most places


3

I know it's the answer nobody likes, but one of the easiest and simplest ways to deal with any kind of spam is to get a new e-mail address, username, phone number, whatever. If you're getting that many messages a day, some real creeps have your info, best to abandon the account and start over with one they don't know about. The only other alternative is ...


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