From: Wojtek Bogusz on
hi, could you please help me to understand is this possible with postfix
configuration:

i have postfix installed on the gateway computer and also on the
internal mail server.
the internal mail server accepts emails only from LAN addresses and does
not require authentication from users to send email using local address
in 'from' field.
gateway does require authentication and is using SASL and TLS and
accepts email also from outside LAN.

my problem is that there is lots of spam delivered using local address
both in 'to' and 'from' fields. i can use
"reject_unauthenticated_sender_login_mismatch" in main.cf on the gateway
as in:

smtpd_sender_restrictions = check_sender_access
hash:/etc/postfix/sender_access, reject_non_fqdn_sender,
reject_unknown_sender_domain, reject_unauthenticated_sender_login_mismatch

but than all the emails from internal email server are being rejected,
as they come not authenticated.

is there any setting that would make postfix allow sending messages with
local address as 'from' on connections from LAN IP and request
authentication on all emails coming from outside IP when using local
address in 'from' field?

i am not sure i manage to explain myself well. please let me know.
cheers, Wojtek

From: Noel Jones on
On 7/12/2010 8:59 AM, Wojtek Bogusz wrote:
> hi, could you please help me to understand is this possible with postfix
> configuration:
>
> i have postfix installed on the gateway computer and also on the
> internal mail server.
> the internal mail server accepts emails only from LAN addresses and does
> not require authentication from users to send email using local address
> in 'from' field.
> gateway does require authentication and is using SASL and TLS and
> accepts email also from outside LAN.
>
> my problem is that there is lots of spam delivered using local address
> both in 'to' and 'from' fields. i can use
> "reject_unauthenticated_sender_login_mismatch" in main.cf on the gateway
> as in:
>
> smtpd_sender_restrictions = check_sender_access
> hash:/etc/postfix/sender_access, reject_non_fqdn_sender,
> reject_unknown_sender_domain, reject_unauthenticated_sender_login_mismatch
>
> but than all the emails from internal email server are being rejected,
> as they come not authenticated.
>
> is there any setting that would make postfix allow sending messages with
> local address as 'from' on connections from LAN IP and request
> authentication on all emails coming from outside IP when using local
> address in 'from' field?
>
> i am not sure i manage to explain myself well. please let me know.
> cheers, Wojtek
>

Use "permit_mynetworks" before
"reject_unauthenticated_sender_login_mismatch"

-- Noel Jones

From: Wojtek Bogusz on
thank you Noel. so simple :-) and it works. regards, Wojtek

Noel Jones wrote:
> On 7/12/2010 8:59 AM, Wojtek Bogusz wrote:
>> hi, could you please help me to understand is this possible with postfix
>> configuration:
>>
>> i have postfix installed on the gateway computer and also on the
>> internal mail server.
>> the internal mail server accepts emails only from LAN addresses and does
>> not require authentication from users to send email using local address
>> in 'from' field.
>> gateway does require authentication and is using SASL and TLS and
>> accepts email also from outside LAN.
>>
>> my problem is that there is lots of spam delivered using local address
>> both in 'to' and 'from' fields. i can use
>> "reject_unauthenticated_sender_login_mismatch" in main.cf on the gateway
>> as in:
>>
>> smtpd_sender_restrictions = check_sender_access
>> hash:/etc/postfix/sender_access, reject_non_fqdn_sender,
>> reject_unknown_sender_domain,
>> reject_unauthenticated_sender_login_mismatch
>>
>> but than all the emails from internal email server are being rejected,
>> as they come not authenticated.
>>
>> is there any setting that would make postfix allow sending messages with
>> local address as 'from' on connections from LAN IP and request
>> authentication on all emails coming from outside IP when using local
>> address in 'from' field?
>>
>> i am not sure i manage to explain myself well. please let me know.
>> cheers, Wojtek
>>
>
> Use "permit_mynetworks" before
> "reject_unauthenticated_sender_login_mismatch"
>
> -- Noel Jones