Re: Marketo emails showing up as BULK - with no ability to show images

SanfordWhiteman
Level 10 - Community Moderator

Re: Marketo emails showing up as BULK - with no ability to show images

Your domain must appear in the header if it's signed by your domain. Otherwise it's being single-signed only.

Dan_Stevens_
Level 10 - Champion Alumni

Re: Marketo emails showing up as BULK - with no ability to show images

I just sent myself another test email and now notice dual DKIM signatures - it appears it was just enabled a litte while ago:

DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1479161974;

    s=m1; d=avanade.com; i=@avanade.com;

    h=Date:From:To:Subject:MIME-Version:Content-Type;

DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1479161974;

    s=m1; d=mktosender.com; i=@mktosender.com;

    h=Date:From:To:Subject:MIME-Version:Content-Type;

Is there any risk in having this signed by both our domain and Marketo's - especially if recipient email servers block all Marketo emails?

SanfordWhiteman
Level 10 - Community Moderator

Re: Marketo emails showing up as BULK - with no ability to show images

If you had a dedicated IP, which serves the purpose (to a degree) of obscuring the Marketo origins of your emails, then it could be questionable to opt back in to being Marketo-connected.

Otherwise, you'd be getting blocked by IP and/or envelope sender anyway, not by a 3rd-party DKIM signature.

Signing an email shows the recipient that there's someone taking end-to-end responsibility for the email content (as opposed to merely permitting the email server to use a sender domain, which is the best SPF can do). If the signer is the same as the From: address domain, that's considered a first-party or "author" signature -- the person who authored the content also signed it. That's the best use of DKIM.

If Marketo is throwing in a 3rd-party signature, that's not going to hurt anything unless the recipient blacklists or negatively weights by DKIM domain. That's pretty rare, but it can happen. DKIM is more often used for positive weighting. It's also a great tool for selective whitelisting because a recipient can say they allow emails that are *signed* and thus attributable to a given domain as opposed to emails that *claim* (via the forgeable From: or MAIL FROM:) to be from that domain.

SanfordWhiteman
Level 10 - Community Moderator

Re: Marketo emails showing up as BULK - with no ability to show images

I'd add, too, that Marketo co-signing mail from trusted IPs (and not from untrusted IPs) is a good way to denote that those instances are at least somewhat policed/proper.

Whether "greater than zero trust" is enough to whitelist on in the real world is anothe matter.

SanfordWhiteman
Level 10 - Community Moderator

Re: Marketo emails showing up as BULK - with no ability to show images

I started to look at the source and noticed in the email header that DKIM is signed by mktosender.com. Shouldn't this be our domain?

Certainly if you are publishing the DKIM pubkey on your domain then it should be using your domain. I think they've been mixing things up lately, but luckily it hasn't affected my "legacy" instances.

Dan_Stevens_
Level 10 - Champion Alumni

Re: Marketo emails showing up as BULK - with no ability to show images

Should I raise this issue with Marketo or our own IT team?

Dan_Stevens_
Level 10 - Champion Alumni

Re: Marketo emails showing up as BULK - with no ability to show images

How do you view the source code of an email in OWA?  When I click "view message details", it just provides the email header details and a bunch of encrypted code.  In the Outlook desktop client, it's viewed here:

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SanfordWhiteman
Level 10 - Community Moderator

Re: Marketo emails showing up as BULK - with no ability to show images

I think in OWA without extensions the best you have is view-source (that is, browser view-source).