Help with new mailscanner install w/ sendmail CentOS7

[Peter Lemieux]

I don't think SRS will help because the "spoofing" error depends on the From 
address in the message body, not the envelope sender.  All my outbound 
listserver traffic has owner-listname at lists.example.com as the envelope 
sender.  If Microsoft relied only on the envelope and ignored the From 
header in the message body, this problem would disappear.

Peter


On 11/04/2016 11:26 AM, Jerry Benton wrote:
> You can also implement SRS on your server.
> https://en.wikipedia.org/wiki/Sender_Rewriting_Scheme
>
>
> -
> Jerry Benton
> www.mailborder.com
> +1 - 844-436-6245
>
>
> -----Original Message-----
> From: Peter Lemieux <mailscanner at replies.cyways.com>
> Reply: MailScanner Discussion <mailscanner at lists.mailscanner.info>
> Date: November 4, 2016 at 11:24:24 AM
> To: MailScanner Discussion <mailscanner at lists.mailscanner.info>
> Subject:  Re: Help with new mailscanner install w/ sendmail CentOS7
>
>> This is something that Microsoft implemented for accounts using their hosted
>> mail services without thinking about the effects it might have on
>> listservers. They are following in the "august" footsteps of Yahoo and AOL
>> whose implementation of DMARC has also caused serious problems for
>> listserver administrators.
>>
>> This list, like the ones I manage, puts the sender's From address in the
>> headers rather than using a generic one like owner-listname at example.com.
>> Microsoft has now chosen to view all messages where the From address matches
>> the recipient's address as "spoofed." This policy only affects the copy of
>> the message being sent back to you. Other subscribers will see the message
>> when redistributed by the listserver.
>>
>> Microsoft clearly refuses to believe the SPF record even when it indicates
>> that the sending server is legitimate. I'm seeing this problem occur on the
>> lists I manage despite having correct SPF data in my DNS.
>>
>> You can look into methods of whitelisting the sending server or sending
>> domain, in this case lists.mailscanner.info. I've seen one complaint at
>> http://answers.microsoft.com/en-us/msoffice/forum/msoffice_o365admin-mso_other/listserv-messages-fail-o365s-fraud-detection/7ab75018-43fc-4d9e-b716-85f7f2418d3c.
>> The reply from the Microsoft support person shows they are entirely
>> clueless about why this policy affects listservers.
>>
>> I dealt with the Yahoo and AOL problems by rewriting the sender's address so
>> it reads
>> someone=yahoo.com at lists.example.com
>> That passes the DMARC tests since the message originates on the legitimate
>> server for lists.example.com. I hope not to have to add Outlook and company
>> to the list of domains for which I do rewriting, but I suspect it may come
>> to that.
>>
>> Google and GMail also treat messages where the From and To are identical as
>> likely spam. I've had to tell my subscribers using those services to look
>> in their spam folders when they don't see their postings to my listserver in
>> their inboxes.
>>
>> Peter
>>
>>
>> On 11/03/2016 07:45 PM, Jerry Benton wrote:
>>> Maybe Mark can provide more info when he has time.
>>>
>>>
>>> On Thursday, November 3, 2016, Paul Scott > > > wrote:
>>>
>>> Hello Jerry. Interesting. I see this message coming back on each send:____
>>>
>>> __ __
>>>
>>>
>>>
>>> This sender failed our fraud detection checks and may not be who they appear to be. Learn
>> about spoofing
>>> ____
>>>
>>> __ __
>>>
>>> __ __
>>>
>>> Not sure why.____
>>>
>>> __ __
>>>
>>> Paul Scott____
>>>
>>> __ __
>>>
>>> __ __
>>>
>>> *From:*MailScanner [mailto:mailscanner-bounces+sales
>>> <_e(%7B%7D,'cvml','mailscanner-bounces%2Bsales');>=edenusa.com at lists.mailscanner.info
>>> <_e(%7B%7D,'cvml','edenusa.com at lists.mailscanner.info');>]
>>> *On Behalf Of *Jerry Benton
>>> *Sent:* Thursday, November 03, 2016 4:40 PM
>>> *To:* MailScanner Discussion > > <_e(%7B%7D,'cvml','mailscanner at lists.mailscanner.info');>>
>>> *Subject:* Re: Help with new mailscanner install w/ sendmail CentOS7____
>>>
>>> __ __
>>>
>>> I see the email you sent.____
>>>
>>> -____
>>>
>>> Jerry Benton____
>>>
>>> www.mailborder.com ____
>>>
>>> +1 844-436-6245 ext 707____
>>>
>>> sent via mobile____
>>>
>>>
>>> On Nov 3, 2016, at 19:37, Paul Scott > > <_e(%7B%7D,'cvml','sales at edenusa.com');>> wrote:____
>>>
>>> The MailScanner Discussion list is now rejecting me. Any idea why?
>>>
>>> -----Original Message-----
>>> From: MailScanner
>>> [mailto:mailscanner-bounces+sales=edenusa.com at lists.mailscanner.info
>>> <_e(%7B%7D,'cvml','mailscanner-bounces%2Bsales%5Cx3dedenusa.com at lists.mailscanner.info');>]
>>> On Behalf Of Mark Sapiro
>>> Sent: Thursday, November 03, 2016 8:48 AM
>>> To: mailscanner at lists.mailscanner.info
>>> <_e(%7B%7D,'cvml','mailscanner at lists.mailscanner.info');>
>>> Subject: Re: Help with new mailscanner install w/ sendmail CentOS7
>>>
>>> On 11/02/2016 10:11 PM, Daniel Cole wrote:
>>>
>>> ____
>>>
>>> __ __
>>>
>>> I believe the issue is that Sendmail is not configured to run
>>> separate ____
>>>
>>> for inbound and outbound as per
>>> https://www.mailscanner.info/sendmail/
>>> ​.____
>>>
>>> If I send mail I can see that sendmail is processing it (and it
>>> gets ____
>>>
>>> delivered as expected), but MailScanner doesnt touch it.____
>>>
>>> __ __
>>>
>>> __ __
>>>
>>> The details on that page dont quite match up wit systemd on
>>> CentOS 7.____
>>>
>>> Can anyone point me in the right direction please?____
>>>
>>>
>>>
>>> The information in the issue at
>>>>>> may help.
>>>
>>> --
>>> Mark Sapiro > > <_e(%7B%7D,'cvml','mark at msapiro.net');>> The
>>> highway is for gamblers,
>>> San Francisco Bay Area, California better use your sense - B. Dylan
>>>
>>>
>>> --
>>> MailScanner mailing list
>>> mailscanner at lists.mailscanner.info
>>> <_e(%7B%7D,'cvml','mailscanner at lists.mailscanner.info');>
>>> http://lists.mailscanner.info/mailman/listinfo/mailscanner
>>>
>>>
>>>
>>>
>>> --
>>> MailScanner mailing list
>>> mailscanner at lists.mailscanner.info
>>> <_e(%7B%7D,'cvml','mailscanner at lists.mailscanner.info');>
>>> http://lists.mailscanner.info/mailman/listinfo/mailscanner
>>> ____
>>>
>>>
>>>
>>> --
>>>
>>> --
>>> Jerry Benton
>>> Mailborder Systems
>>> www.mailborder.com
>>>
>>>
>>>
>>>
>>>
>>
>>
>> --
>> MailScanner mailing list
>> mailscanner at lists.mailscanner.info
>> http://lists.mailscanner.info/mailman/listinfo/mailscanner
>>
>>
>
>