The Community Forums

Interact with an entire community of cPanel & WHM users!
  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Remove Fail from email filter options - Backscatter

Discussion in 'E-mail Discussions' started by sparek-3, Feb 5, 2016.

  1. sparek-3

    sparek-3 Well-Known Member

    Joined:
    Aug 10, 2002
    Messages:
    1,384
    Likes Received:
    23
    Trophy Points:
    38
    cPanel Access Level:
    Root Administrator
    Is this how new feature requests is suppose to work? Make a new feature request and then start a thread on the forums to plug that feature request?

    I've made a feature request to request cPanel to remove the Fail With Message option from email filter's in end-user's cPanel:

    Remove Fail from email filter options - Backscatter

    I would encourage people to read it and vote for it.
     
  2. Infopro

    Infopro cPanel Sr. Product Evangelist
    Staff Member

    Joined:
    May 20, 2003
    Messages:
    14,474
    Likes Received:
    202
    Trophy Points:
    63
    Location:
    Pennsylvania
    cPanel Access Level:
    Root Administrator
    Twitter:
    No. How Feature Requests work is posted here:
    https://forums.cpanel.net/pages/cpfeatures/

    Here:
    Home »Server Configuration »Tweak Settings, Mail tab, are setting for this I believe.

     
  3. sparek-3

    sparek-3 Well-Known Member

    Joined:
    Aug 10, 2002
    Messages:
    1,384
    Likes Received:
    23
    Trophy Points:
    38
    cPanel Access Level:
    Root Administrator
    So you don't talk up your feature request in the forums? How do people find the new feature requests? Seems most people read the forums. I can understand cPanel's development team wanting feature requests in a central location. But I can also see the forums as being a venue to encourage other people to read the feature request and vote and/or give feedback on that feature request.

    The setting you are talking about, in Tweak Settings, is for the default address. I agree with this. When Fail is used for the default address, the message is never accepted (never given an exim message id) on the server. But when using filters, end-user filters, those messages are accepted by the server and then the filter tries to bounce it back. Then that bounceback message gets caught in bounceback hell (backscatter).
     
  4. Infopro

    Infopro cPanel Sr. Product Evangelist
    Staff Member

    Joined:
    May 20, 2003
    Messages:
    14,474
    Likes Received:
    202
    Trophy Points:
    63
    Location:
    Pennsylvania
    cPanel Access Level:
    Root Administrator
    Twitter:
    I've never experienced that in over 10 years so can't properly assist you there. I trust this advice:
    Why you should use :fail:

    The forums is where Feature Requests were posted, and it was a lot of work to maintain:
    Feature Requests Have a New Home Starting Today

    They visit the Feature Requests site, search for a feature (hopefully) before posting one of their own. The Feature Requests site is very active, people find it.
     
    mtindor likes this.
  5. sparek-3

    sparek-3 Well-Known Member

    Joined:
    Aug 10, 2002
    Messages:
    1,384
    Likes Received:
    23
    Trophy Points:
    38
    cPanel Access Level:
    Root Administrator
    Well, chirpy is right with what he says on that link. But he is referring to the default address. Let's make sure we're differentiating these things correctly:

    Default address != ANY filter

    I think this is a misunderstanding that most end-users don't get. And it may be a misunderstanding that cPanel is not understanding. Everyone thinks fail is what you should do all the time, but they don't understand the context of where it is being used.

    Consider an SMTP transaction, when sending to a non-existant email account:

    Code:
    # telnet mail.yourmailserver.com 25
    Trying XX.XX.XX.XX...
    Connected to mail.yourmailserver.com
    Escape character is '^]'.
    220-mail.yourmailserver.com ESMTP Exim 4.85 #2 Fri, 05 Feb 2016 12:44:12 -0500
    220-We do not authorize the use of this system to transport unsolicited,
    220 and/or bulk e-mail.
    EHLO servername
    250-mail.yourmailserver.com Hello servername
    250-SIZE 52428800
    250-8BITMIME
    250-PIPELINING
    250-AUTH PLAIN LOGIN
    250-STARTTLS
    250 HELP
    mail from: <postmaster@servername.com>
    250 OK
    rcpt to: <idontexist@yourmailserver.com>
    550 No Address Here
    DATA
    503-All RCPT commands were rejected with this error:
    503-No Address Here
    503 Valid RCPT command must precede DATA
    This is correct. This is the DEFAULT ADDRESS being set to fail.


    But an email that has a filter:

    Code:
    # telnet mail.yourmailserver.com 25
    Trying XX.XX.XX.XX...
    Connected to mail.yourmailserver.com.
    Escape character is '^]'.
    220-mail.yourmailserver.com ESMTP Exim 4.85 #2 Fri, 05 Feb 2016 12:48:29 -0500
    220-We do not authorize the use of this system to transport unsolicited,
    220 and/or bulk e-mail.
    EHLO servername
    250-mail.yourmailserver.com Hello servername
    250-SIZE 52428800
    250-8BITMIME
    250-PIPELINING
    250-AUTH PLAIN LOGIN
    250-STARTTLS
    250 HELP
    mail from: <imnotarealemailaddress@servername.com>
    250 OK
    rcpt to: <iexistbutihaveafiltersettofail@yourmailserver.com>
    250 Accepted
    DATA
    354 Enter message, ending with "." on a line by itself
    From: <imnotarealemailaddress@servername.com>
    To: <iexistbutihaveafiltersettofail@yourmailserver.com>
    Subject: Test Message
    
    I'm the part of the message that's going to hit the filter.
    .
    250 OK id=1aRkUo-0004Su-O4
    quit
    221 mail.yourmailserver.com closing connection
    Connection closed by foreign host.
    In this example, this message was accepted (note id=1aRkUo-0004Su-O4). But because iexistbutihaveafiltersettofail@yourmailserver.com has a filter set to filter messages that contain "I'm the part of the message that's going to hit the filter." and fail them, then yourmailserver.com is going to try to send that fail message to imnotarealemailaddress@servername.com. But it's not going to work, because imnotarealemailaddress@servername.com isn't a real email address that is accepting messages. This is bounceback hell.
     
  6. Infopro

    Infopro cPanel Sr. Product Evangelist
    Staff Member

    Joined:
    May 20, 2003
    Messages:
    14,474
    Likes Received:
    202
    Trophy Points:
    63
    Location:
    Pennsylvania
    cPanel Access Level:
    Root Administrator
    Twitter:
    I'm not mail server expert and should keep out of this. If its stuck in the queue why do you mention backscatter/bounceback?
     
  7. sparek-3

    sparek-3 Well-Known Member

    Joined:
    Aug 10, 2002
    Messages:
    1,384
    Likes Received:
    23
    Trophy Points:
    38
    cPanel Access Level:
    Root Administrator
    Because that's what backscatter is? The message is stuck in queue with no place to go.

    Backscatter (email) - Wikipedia, the free encyclopedia

    "Backscatter occurs because worms and spam messages often forge their sender address and a misconfigured mail server, which has Delivery Status Notifications enabled sends a bounce message to this address. This normally happens when a mail server is configured to relay a message to an after-queue processing step, for example, an antivirus scan or spam check, which then fails, and at the time the antivirus scan or spam check is done, the client already has disconnected. In those cases, it's normally not possible to reject at the SMTP stage, since a client would time-out while waiting for the antivirus scan or spam check to finish. The best thing to do in this case, is then silently drop the message, e.g., pipe it to /dev/null."
     
  8. Infopro

    Infopro cPanel Sr. Product Evangelist
    Staff Member

    Joined:
    May 20, 2003
    Messages:
    14,474
    Likes Received:
    202
    Trophy Points:
    63
    Location:
    Pennsylvania
    cPanel Access Level:
    Root Administrator
    Twitter:
    Yea, I should probably back out of this quietly now I think... :-p

    But I'm curious enough to ask, how big of a problem is this for you? If user sets up a filter you speak of, it causes issues and my mail queue starts filling up. I've been keeping an eye on that for years and the moment I see the issue, I sort it out.

    What did I do to sort it out though? Remove the end-users filter? If yes, that's easy enough.

    How many users do that though? I assume often enough that you were compelled to post a new Feature Request and start this thread.
     
  9. sparek-3

    sparek-3 Well-Known Member

    Joined:
    Aug 10, 2002
    Messages:
    1,384
    Likes Received:
    23
    Trophy Points:
    38
    cPanel Access Level:
    Root Administrator
    End-users keep re-enabling the filter using fail. You can tell them until you're blue in the face, and it doesn't sink in. If the option is there, some users will click on it.

    It's not a lot of users. But it is a nuisance when it does happen. And there's been at least one occasion where the user wrote back "why is the option there if we're not suppose to use it?" Because I can't remove it and the only people that can remove it apparently don't want to listen to reason.
     
  10. Infopro

    Infopro cPanel Sr. Product Evangelist
    Staff Member

    Joined:
    May 20, 2003
    Messages:
    14,474
    Likes Received:
    202
    Trophy Points:
    63
    Location:
    Pennsylvania
    cPanel Access Level:
    Root Administrator
    Twitter:
    What is this deadly filter you speak of exactly? I've just re-read the Feature Request and this thread and still not sure what it is.
     
  11. sparek-3

    sparek-3 Well-Known Member

    Joined:
    Aug 10, 2002
    Messages:
    1,384
    Likes Received:
    23
    Trophy Points:
    38
    cPanel Access Level:
    Root Administrator
    I tell you what, set up a filter that fails with message on an email account that you own. Let me know what that email address is and what the filter criteria is, and I'll show you.
     
  12. Infopro

    Infopro cPanel Sr. Product Evangelist
    Staff Member

    Joined:
    May 20, 2003
    Messages:
    14,474
    Likes Received:
    202
    Trophy Points:
    63
    Location:
    Pennsylvania
    cPanel Access Level:
    Root Administrator
    Twitter:
    Ok. I've opened a private conversation with you here on the forum.
     
Loading...

Share This Page