> On Dec 9, 2016, at 5:59 PM, Luke Martinez <luke.marti...@sendgrid.com> wrote: > > Thanks for the insights Steve, > > Any thoughts on why the indentation would be different? As far as I know, > this message was built once, and then it was sent to several different > recipients. I can't guess why the results would be different when being sent > to different outlook.com recipients. Also noteworthy...Subsequent test > messages (different content, but same config) sent to the same addresses > produced different results (attached)
Looks like someone along the delivery path is expanding tabs, but it's hard to say more without looking at wider data. Unless I saw something to suggest otherwise I'd assume that it's something to do with the delivery path rather than the recipient. I'd look at the smarthosts they went through (is something configured differently on them?) and the MXes that received them. The messages have differing indentation on the X-Microsoft-Exchange-Diagnostics headers, which strongly suggests it's inside something at Microsoft. You could reach out to someone who's at Microsoft and ask them to take a look. Though I'd probably try injecting identical-ish messages into outlook.com's dozens of MXes and see if there were any pattern first. Easy enough to black-box it with swaks and a shell script. Cheers, Steve > > On Fri, Dec 9, 2016 at 5:57 PM, Steve Atkins <st...@blighty.com> wrote: > > > On Dec 9, 2016, at 3:36 PM, Luke Martinez via mailop <mailop@mailop.org> > > wrote: > > > > I've got some DKIM failures I'm having trouble figuring out. Below are two > > identical messages sent to two different outlook.com recipients from the > > same infrastructure. One is failing DKIM, the other isn't. > > > > This issue is semi-repeatable, with some addresses failing DKIM and others > > passing seemingly at random. > > > > I was wondering if anyone could help me identify the cause of the DKIM > > failure, or let me know if this is just a thing that happens on occasion. > > I've attached the full messages and pasted the two headers. > > dkimpass.txt indents some lines (e.g. DECK THE HALLS) with three tabs, while > dkimfail.txt indents those same lines with six spaces. > > For mail that otherwise looks like it's coming from the same template that's > very suspicious. > > Cheers, > Steve > > > > > -- > > Luke Martinez > Team Lead | Email Delivery > 520.400.5693 > <jkdkimpass.txt> _______________________________________________ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
