Help with new mailscanner install w/ sendmail CentOS7

Peter Lemieux mailscanner at replies.cyways.com
Fri Nov 4 15:24:01 UTC 2016


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 <sales at edenusa.com
> <mailto:sales at edenusa.com>> 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
>     <http://aka.ms/LearnAboutSpoofing>____
>
>     __ __
>
>     __ __
>
>     Not sure why.____
>
>     __ __
>
>     Paul Scott____
>
>     __ __
>
>     __ __
>
>     *From:*MailScanner [mailto:mailscanner-bounces+sales
>     <javascript:_e(%7B%7D,'cvml','mailscanner-bounces%2Bsales');>=edenusa.com at lists.mailscanner.info
>     <javascript:_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 <mailscanner at lists.mailscanner.info
>     <javascript:_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 <http://www.mailborder.com>____
>
>     +1 844-436-6245 ext 707____
>
>     sent via mobile____
>
>
>     On Nov 3, 2016, at 19:37, Paul Scott <sales at edenusa.com
>     <javascript:_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
>         <javascript:_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
>         <javascript:_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/
>             <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
>         <https://github.com/MailScanner/v5/issues/23
>         <https://github.com/MailScanner/v5/issues/23>> may help.
>
>         --
>         Mark Sapiro <mark at msapiro.net
>         <javascript:_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
>         <javascript:_e(%7B%7D,'cvml','mailscanner at lists.mailscanner.info');>
>         http://lists.mailscanner.info/mailman/listinfo/mailscanner
>         <http://lists.mailscanner.info/mailman/listinfo/mailscanner>
>
>
>
>         --
>         MailScanner mailing list
>         mailscanner at lists.mailscanner.info
>         <javascript:_e(%7B%7D,'cvml','mailscanner at lists.mailscanner.info');>
>         http://lists.mailscanner.info/mailman/listinfo/mailscanner
>         <http://lists.mailscanner.info/mailman/listinfo/mailscanner>____
>
>
>
> --
>
> --
> Jerry Benton
> Mailborder Systems
> www.mailborder.com <http://www.mailborder.com>
>
>
>
>
>


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