Please whitelist cPanel in your adblocker so that you’re able to see our version release promotions, thanks!

The Community Forums

Interact with an entire community of cPanel & WHM users!

Block e-mail addresses from e-mailing any user on server

Discussion in 'E-mail Discussion' started by jtgroup, Mar 4, 2019.

Tags:
  1. jtgroup

    jtgroup Active Member

    Joined:
    Nov 21, 2017
    Messages:
    30
    Likes Received:
    2
    Trophy Points:
    8
    Location:
    UK
    cPanel Access Level:
    Root Administrator
    Hello everyone,

    We have been having a lot of issues with spam recently and have decided to start managing some of it in house rather than relying on automatic filters.

    This morning I have created a block list based on the instructions here ( WHM - Block server from receiving e-mails from particular domains ) to block particular domains from e-mailing anyone on the server.

    My next step is to block individual accounts from being able to contact anyone on any domain hosted on our server. The problem being that we still get the occasional person spamming from say a Yahoo account. Obviously we do not want to block every Yahoo account from being able to send us messages but it would be helpful if we could block individual ones.

    Would it be possible to add individual e-mail addresses to the same blacklist (as I created earlier using those steps) or is that one only suitable for full domains?

    I hope that makes sense.

    Kind regards


    James
     
    #1 jtgroup, Mar 4, 2019
    Last edited: Mar 4, 2019
  2. keat63

    keat63 Well-Known Member

    Joined:
    Nov 20, 2014
    Messages:
    1,306
    Likes Received:
    92
    Trophy Points:
    28
    cPanel Access Level:
    Root Administrator
    Youre creating a rod for your own back and an almost impossible task.
    Compiling lists of offending spammers would be all but impossible.
    You might get 10 spam emails from one sender and none ever again.
    They tend to use bots, with throw away email addresses.

    An easier solution for starters would be to use RBL's.
    In Exim Config under RBL's, click manage custome rbl's and add the following few entries.
    Code:
    AbuseAT                cbl.abuseat.org      https://www.abuseat.org/
    Barracuda             b.barracudacentral.org      http://www.barracudacentral.org/rbl/removal-request
    SemFresh30         fresh30.spameatingmonkey.net      https://spameatingmonkey.com/services/SEM-FRESH30
    SemURIBL            uribl.spameatingmonkey.net      https://spameatingmonkey.com/services/SEM-URI
    semblack              bl.spameatingmonkey.net      https://spameatingmonkey.com/services/SEM-BLACK
    spamcop              bl.spamcop.net      http://spamcop.net/bl.shtml
    
    screenshot attached
     

    Attached Files:

    • rbl.jpg
      rbl.jpg
      File size:
      151.6 KB
      Views:
      3
    #2 keat63, Mar 4, 2019
    Last edited by a moderator: Mar 4, 2019
    rpvw likes this.
  3. keat63

    keat63 Well-Known Member

    Joined:
    Nov 20, 2014
    Messages:
    1,306
    Likes Received:
    92
    Trophy Points:
    28
    cPanel Access Level:
    Root Administrator
    Also, CSF mailscanner has tools built in to block specific email addresses.
    You can blacklist at the click of a button.
    It's not free, but it's not expensive either.
     
  4. jtgroup

    jtgroup Active Member

    Joined:
    Nov 21, 2017
    Messages:
    30
    Likes Received:
    2
    Trophy Points:
    8
    Location:
    UK
    cPanel Access Level:
    Root Administrator
    Hi Keat,

    Thank you. I agree and we do use RBLs but some of the time we notice that it takes weeks for them to catch up and block some of the spammers. We'd like to have this in our arsenal as well if possible.

    Would it be possible to add e-mail addresses to that list as well or will it only work with domains?

    Kind regards


    James
     
  5. keat63

    keat63 Well-Known Member

    Joined:
    Nov 20, 2014
    Messages:
    1,306
    Likes Received:
    92
    Trophy Points:
    28
    cPanel Access Level:
    Root Administrator
    Maybe it's possible to create your own RBL and configure exim to use that as well.
    Just point the url to your own file.
    You could 'I guess' put anything you want in your own RBL, but this really would be a thankless task one of which which you will soon get bored of, im sure.

    CSF mailscanner has a gui, you select the email you wish to blacklist and click the blacklist button, but even that is tiresome.

    Some spammers set up an email, use it for a few days, get blacklisted and dump it in favour of another. Those spameatingmonket RBL's look at the age of a domain and block based on this.

    I've also changed the scores on some of the spamassasin rules which has helped a little.
     
  6. cPanelMichael

    cPanelMichael Technical Support Community Manager Staff Member

    Joined:
    Apr 11, 2011
    Messages:
    47,604
    Likes Received:
    2,187
    Trophy Points:
    363
    cPanel Access Level:
    Root Administrator
    Twitter:
    Hello James,

    Have you considered some of the other SPAM prevention methods first to see if blacklisting individual email accounts is still necessary? For instance, the Greylisting feature is very effective tool to preventing incoming SPAM.

    Otherwise, one available option to block an individual email account is to simply setup a custom Exim system filter rule using the instructions on the document below:

    How to Customize the Exim System Filter File - cPanel Knowledge Base - cPanel Documentation

    This won't add it to your custom RBL list, but it's able to effectively prevent an individual email account from sending emails to any of the domains hosted on the server.

    Thank you.
     
    Stop hovering to collapse... Click to collapse... Hover to expand... Click to expand...
Loading...

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice