How can I block emails with no sender?

The most effective way I have found that seems to work and Does not delete all your emails is on a Mac go to preferences “Rules” create one rule don’t involve any any other rules with it .. “From” “Does Not Contain” “ . “ .. then create a mailbox on your Mac called “ filtered mail “ have this rule send any mail to this box… only use it for this rule.. don’t add it to a pre-existing rule. Then, when you go to your mail, you look in the filtered box, anything that should be kept for whatever reason you can transfer back to the inbox and anything else you just select all and delete.

Here's what I did. It seems to be working. Set up an Apple Mail rule that sends all mail where "From" "does not contain" "." to trash.

Have you tried setting up a rule inside Mail that moves a message to a folder that you designate if the sender DOES NOT contain a period character . or DOES NOT contain the @ symbol? The senders that are legitimate seem to all be in the form of xxx@yyy.zzz so a sender identified only as (no sender) would be flagged as not having a period (.) or not having an @ symbol (@) and would be sent to that spam folder. After determining that the rule works as you want, you could send those messages to the Trash instead of a folder.

I'm RoadRunner also. This worked for me:

Set up a rule "From", "does not contain", "@".

Who is your email provider? If Spectrum, a very good response can be found at: https://community.spectrum.net/discussion/172729/how-do-you-stop-spam-with-no-sender. Scroll down to "kpbr1600 September 2023". Here's his(?) reply:

"Go to the Spectrum email page at webmail.spectrum.net. Under

Settings, add an email filter to block any Sender that does not include

the @ symbol. It’s been working great for me!"

Spectrum also advises switching to a secure web based email provider.

One of the suggestions worked! Set up a rule "From", "does not contain", "@". Worked for me!

Set up a rule "From", "does not contain", "@", "delete". Worked for me.

The only remedy I came up with was to go to my internet provider (Spectrum) and dive into my email settings there, marking one spammer with no email return address as "junk mail" and they automatically moved all of them to the junk mail folder. When I returned to my Mac's email page, they were all in the junk mail folder as well. I hope this solves the problem.

Set up a rule "From", "does not contain", "@".

Have you tried a Mail rule such as:

[ From ] [ Contains ] no sender

and then move to Trash?

Some thing I have tried, and seems to have worked is create a rule that states from does not contain . And just create a filter folder for anything to go to this way, you can easily double check and see if it works. It does not seem to delete any of my emails. It was suggested to create a rule that just had an.@ but that filters every email

I would suggest trying what I did create a rule that states sender does not contain, and just put a period, and then create a filter box for your mail to go into and check it for the first few days. Other rules that I have tried seem to have Taken every email I’ve gotten and filtered it. This one seems to have worked.

Haven't tried this with Apple Mail.

Some Windows users were having the same problem with "No sender" spam, and someone came up with the idea to set their mail filtering to move ALL e-mail into (a junk folder, or the trash), EXCEPT for e-mails where the sender field contained a '@'. The idea being that all legitimate e-mails (as well as many others) would have the '@'.

https://answers.microsoft.com/en-us/outlook_com/forum/all/how-can-i-block-spam-email-with-no-sender-email/1ad8e13e-8dc9-4d7f-9b7c-24217094ec3b?page=1

I was on the phone with Apple support for another matter and brought this up. I was told there's nothing that can be done about it and to just delete them as they come. As good as Apple support has been for me, this left me wondering, what the heck?