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Level 2

235 points

General Mail Settings Changing Automatically - Server

Hello,

I am having a major issue with a fairly new installation of 10.6 Leopard Server. My settings under the General tab are changing on their own and blocking around 99% of mail. Under Domain Name. I enter mydomain.com but every few hours the entry changes to the word 'local' rendering the mail server non functional pretty well sending 554 errors to almost every incoming mail. I know Main.cf in the Postfix folder, has these settings and sure enough when I check it has been changed. My bigger question is what controls the Main.cf file other than the mail settings GUI? Luckily this server still has 10.5 Server on a separate Raid so I have had to reboot back into the old system until this is resolved. This post is now more specific than my last thread.

Any help would appreciated, thanks.

Posted on Dec 31, 2011 7:56 AM

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MrHoffman

Community+ 2024

Level 10

117,115 points

Posted on Jan 1, 2012 6:16 AM

Launch Terminal.app and issue the command:

sudo changeip -checkhostname

The usual reason for these sorts of weirdnesses involves an invalid local DNS configuration.

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23 replies

Darryl M Author

Level 2

235 points

Jan 6, 2012 5:02 PM in response to MrHoffman

But even with that aside, it still does not explain why the Domain Name in General settings changes, which it did during the night rendering all mail as 554 error. I've since went back to 10.5, at this point unless I can find a reason why it is happening, can't afford to remain booted into 10.6.

Jul 24, 2012 11:58 PM in response to Darryl M

Did you ever figure out a solution to this?

I'm seeing a similar problem with 10.6.8, it seems to happen whenever my DSL line goes down and then back up. My "solution" at this point is to use a script which watches the file and puts it back whenever it changes.

Darryl M Author

Level 2

235 points

Jul 25, 2012 3:39 AM in response to Douglas Urner

I had tried multiple times to fix the issue but keeps coming back, even stripping the permissions off the file but it was still changing. I eventually went back to 10.5.8 and gave up on the 10.6.

Currently setting up a SAS RAID with Mtn Lion Server once it;s released and will give it another go but until then 10.5 is in use.

Jul 26, 2012 6:40 AM in response to Darryl M

Having valid DNS is part of the SMTP RFCs. Mountain Lion and Mountain Lion Server will (still) require valid DNS configuration, and other DNS servers will often not respond to a mail server with mismatched reverse DNS; the other servers can drop arriving messages, and may not send messages to the server.

For a related discussion, one of the folks posting here, Douglas Urner, has a related thread on this question.

Jul 26, 2012 11:23 AM in response to MrHoffman

Should be: ..and other mail servers will often...

Darryl M Author

Level 2

235 points

Jul 26, 2012 4:16 PM in response to MrHoffman

Thank you very much for responding again, very appreciated.

Jan 13, 2014 8:53 AM in response to Douglas Urner

I have exactly the same issue. Would you mind posting the script?

Jan 14, 2014 6:44 AM in response to marc herman

Please establish correct local DNS, and establish correct public DNS.

DNS is absolutely critical to a properly-functioning mail server, and misconfigured DNS will cause your messages to be dropped by other servers, and there is absolutely nothing you can do here to prevent other mail servers from discarding your outbound mail, other than either fixing DNS, or using a mail relay.

When operating in a NAT'd network, incorrect local DNS will cause the mail server to get confused about its identity.

Any script that tries to reset the settings when the mail server gets confused by invalid DNS is somewhat of a hack, and the configuration will probably still have transient problems. This in addition to seeing your outbound mail discarded by other mail servers, and some servers refusing to send your server messages.

If you post your (public) domain, somebody here can check it. If you're shy about posting that, there are mail- and DNS-related threads here, here, and here — which describe how to verify public DNS. You'll need to bypass your local DNS to check your public DNS; adding @8.8.8.8 on the dig query causes the dig command to bypass local (NAT'd) DNS and connect to Google DNS. Private DNS is verified with the sudo changeip -checkhostname mentioned earlier, and with the local dig commands.

General Mail Settings Changing Automatically - Server