Re: [SPAM] Re: [vchkpw] Prevent certain users from send emails outside the local domain.

Dear Amit,

Thank you for pointing in right direction.
However, there are some shortcomings of implementing eMPF, I have 
encountered:

Scenario 1: User A has been configured to prevent sending mails to 
external domain.

If user A sends mail to internal domain (permitted by policy), with a 
copy to external domain (denied by policy), the entire mail is rejected.

Scenario 2: Vpopmail has been configured with /defaultdomain/ name in 
~vpopmail/etc/defaultdomain file

With defaultdomain configured, it is not mandatory to supply full 
emailaddress for authenticating with mailserver resulting in eMPF to 
fail and allow all emails.

--
Having said that I have been able to write a workaround for Scenario 2 
but living with Scenario 1 currently.
Any help will be appreciated.

Attached is patch I have created for Scenario 2.

HOWTO for Scenario 2:
------
1. Apply patch
2. Configure and export QMAILDEFAULTDOMAIN variable in the run file for 
SMTP Server
e.g. export QMAILDEFAULTDOMAIN="@example.com"

Thanks & Regards,


On 08-06-12 17:40, Amit Dalia wrote:
> This can be done with the help of eMPF patch with qmail.
>
> With Regards,
> Amit Dalia
>
>
>> ---- Original Message ----
>> From: Todor Petkov <[email protected]>
>> To: [email protected]
>> Sent: Fri, Jun 8, 2012, 17:02 PM
>> Subject: [vchkpw] [SPAM] Re: [vchkpw] Prevent certain users from send emails outside the local domain.
>>
>> On 06/08/2012 01:04 PM, Pritam D. Gautam wrote:
>>> Hi,
>>>
>>> I am required to prevent certain users on my Qmail Server from sending
>>> emails to outside domain.
>>> In my understanding, only IP Addresses can be prevented from relaying!
>>> But that's something which does not work in my environment considering
>>> we have DHCP setup.
>>>
>>> Any help will be appreciated.
>>>
>>> Regards,
>>>
>>>
>>>
>>>
>> Hello,
>>
>>
>> not 100% sure, but I think you can do it via vmoduser and adding -r flag
>> to the user. This, however, will require smtp auth usage.
>> For more information, look at http://www.qmailwiki.org/Vpopmail#vmoduser
>>
>>
>>
>> Regards,
>>
>>
>>
>>
>>
>
> 
>
>




!DSPAM:4fd3371934206430959780!

--- policy.c    2012-06-09 16:15:17.000000000 +0530
+++ /home/pd/policy.c    2012-06-09 16:23:47.000000000 +0530
@@ -119,11 +119,28 @@
    domains_free();
 #endif

-   if (remoteinfo)
+/*----Begin Customization -- PritamDutt (Pd)----------*/
+
+/*
+In case a *defaultdomain* is defined in ~vpopmail/etc/defaultdomain file,
+and client does not provide domain name during authentication process the policy check module fails.
+
+To workaround: following is being done:
+1. QMAILDEFAULTDOMAIN variable is defined and exported in run file of SMTP server
+e.g. export QMAILDEFAULTDOMAIN="@example.com"
+2. The environment variable is extracted and appended to authenticating user id.
+*/
+
+   if (remoteinfo){
+      if (strchr(remoteinfo,'@')==NULL)
+          strcat(remoteinfo,env_get("QMAILDEFAULTDOMAIN"));
       p = remoteinfo;
+   }
    else
       p = mailfrom.s;

+/*----End Customization -- PritamDutt (Pd)----------*/
+
    fprintf(stderr, "policy_check: %s %s -> %s %s (%s)\n",
          rcpthosts(p, strlen(p)) ? "local" : "remote", p,
          rcpthosts(addr.s, strlen(addr.s)) ? "local" : "remote", addr.s,