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.

mx question...

Discussion in 'E-mail Discussions' started by 4u123, Jun 24, 2008.

  1. 4u123

    4u123 Well-Known Member
    PartnerNOC

    Joined:
    Jan 2, 2006
    Messages:
    765
    Likes Received:
    1
    Trophy Points:
    18
    We use the DNS templates to set the mx on all new domains automatically to our anti spam server. So all new domains are set to use an external mx BUT we MUST have the server set to accept mail for those domains.

    This seems to have been working as standard - when using the zone templates, the domains are not being set to remote, which is exactly what we need.

    however, I noticed recently on one server, 5 or 6 domains stopped receiving mail and they all had been added to the remotedomains file without us changing anything. Does anyone know why that might happen ? The only thing I can think of is if I had edited a zone file and forgot to tick the box to make sure the domain accepted mail locally - however, this is not the case. I am always very careful about that.

    I noticed in the tweak settings there is an option...

    What exactly does this do?
     
  2. cPanelKenneth

    cPanelKenneth cPanel Development
    Staff Member

    Joined:
    Apr 7, 2006
    Messages:
    4,458
    Likes Received:
    22
    Trophy Points:
    38
    cPanel Access Level:
    Root Administrator
    It causes cPanel to perform a MX lookup each time the Zone is modified. Based upon the results of the lookup , the files mentioned will be updated.
     
  3. 4u123

    4u123 Well-Known Member
    PartnerNOC

    Joined:
    Jan 2, 2006
    Messages:
    765
    Likes Received:
    1
    Trophy Points:
    18
    Ok can you please tell me if these statements are correct.....

    If I have this option enabled and the customer creates a sub domain or addon domain in cpanel, the server will perform an MX lookup. Because the MX record is an external domain (even if I have previously ticked the option in the dns zone editor to acceptmail locally) it will add the users domain to the remotedomains file.

    In order to prevent this from happening I need to disable this option in the tweak settings ?

    If I disable this option in tweak settings, the server will never add a domain to the remotedomains file unless I either add it manually, or untick the box in the dns zone editor, forcing it to do so.
     
  4. cPanelKenneth

    cPanelKenneth cPanel Development
    Staff Member

    Joined:
    Apr 7, 2006
    Messages:
    4,458
    Likes Received:
    22
    Trophy Points:
    38
    cPanel Access Level:
    Root Administrator
    Those statements are correct for this moment in time.

    The option in the Zone editor only applies when saving the Zone via the Zone Editor. The Option in Tweak Settings is meant to be a global option, always enforced, unless disabled.
     
  5. 4u123

    4u123 Well-Known Member
    PartnerNOC

    Joined:
    Jan 2, 2006
    Messages:
    765
    Likes Received:
    1
    Trophy Points:
    18
    Ok thank you for clarifying.
     
  6. 4u123

    4u123 Well-Known Member
    PartnerNOC

    Joined:
    Jan 2, 2006
    Messages:
    765
    Likes Received:
    1
    Trophy Points:
    18
    I'm very concerned that recent changes to cpanel have caused a problem with this.

    I beleive that the new tweak setting...

    Is ignoring the DNS templates and sets the MX record to the domain instead.


    Just to clarify, it is VERY important for us and for many other cpanel customers using external anti spam boxes that the following set of circumstances be available at all times....


    1. Ability to set MX record on all new accounts and addons via the zone templates upon creation.

    No other process should interfere with this. If you add a new feature that might impact on this, please please dont enable it by default!

    2. Ability to ensure that the domains will remain in "localdomains" and not get added as remote. I understand this is done by disabling the following option...

    It is critical that we are able to retain local delivery with external mx's on all domains. Any change to this would be a total disaster.

    3. Ensure the MX record is not automatically changed by any cpanel process back to the local domain name.

    Currently there are one or two things causing this to happen - I dont know what exactly but we are getting customers every day now saying that they cannot receive email and when I look at their zone file, their MX has reverted back to the domain name without any intervention. Some cpanel process is doing this automatically.

    Again, it is critical that once we have set the MX, it does not get changed unless we change it manually. (We disable the mx function in the customer's interface).

    4. cpanel must understand that a growing number of their customers are using external anti spam servers and any small changes you make can have a massive impact on this functionality. I would urge you to please consider this when developing any process that makes DNS changes.
     
    #6 4u123, Jun 26, 2008
    Last edited: Jun 26, 2008
  7. cPanelDavidG

    cPanelDavidG Technical Product Specialist

    Joined:
    Nov 29, 2006
    Messages:
    11,279
    Likes Received:
    8
    Trophy Points:
    38
    Location:
    Houston, TX
    cPanel Access Level:
    Root Administrator
    MX entries that have been properly set should not be changing themselves upon cPanel updates or as a result of enabling the reverse proxy. I recommend you let our technical analysts take a look at your server to determine why this would be happening: http://tickets.cpanel.net/submit
     
  8. cPanelKenneth

    cPanelKenneth cPanel Development
    Staff Member

    Joined:
    Apr 7, 2006
    Messages:
    4,458
    Likes Received:
    22
    Trophy Points:
    38
    cPanel Access Level:
    Root Administrator
    Out of sync members of a DNS cluster can cause the issues described.
     
  9. 4u123

    4u123 Well-Known Member
    PartnerNOC

    Joined:
    Jan 2, 2006
    Messages:
    765
    Likes Received:
    1
    Trophy Points:
    18
    There are no out of sync servers in our DNS cluster.

    Also, I didnt enable the reverse proxy on any servers. I didnt even know it existed. Your update seemed to enable this automatically without giving us any chance to choose not to use it.

    With regards to MX entries being "properly set". How does one properly set an MX record?

    The way the mx records got set on our servers was either via the zone templates (for new domains) or by manually updating the zone files on the main cluster nameservers and updating the serials using zsu and restarting bind.

    I concede that if a local version of a zone file has not been updated by the cluster and it gets changed by a cpanel process and synced up to the name servers, this would cause a problem. Of course that shows a failure in the cpanel clustering process - or if a handful of zone files serials didnt get updated for some reason when we made the changes, this might explain why a few zone files on the servers contained incorrect info.

    However... In this case, If you hadnt caused these changes to occur without providing the option not to - there wouldnt have been any problems because no local zone files would have been updated. The handful of domains who's zone files were not correct would never have been changed.

    I dont see anyone form cpanel admitting that you made a mistake here, forcing major changes on everyone's servers without telling them. That looks like a pretty big oversight to me!

    If you are going to introduce something that will make changes to all the DNS zones on a server without providing any opt - out option, you should be letting us know well in advance via an advisory email.
     
    #9 4u123, Jun 27, 2008
    Last edited: Jun 27, 2008
Loading...

Share This Page