Hosting email images on our own server - any issues with this?

[Anonymous]

Hey all,

Question about hosting images that we use in a daily account update email we send to our clients.

Engineering put the email together and handles most of the maintenance, they also launch the campaign through the API. They're planning to host the images on our Amazon S3 server rather than in the marketo design studio.

Can anyone think of any issues this may cause? Only thing that occurred to me was that marketo may use these images to know whether someone opened an email or not, though I'm not sure if it just uses a blank pixel for that instead.

I found an old post where Josh Hill​ recommended hosting all email and landing page images on Marketo servers, but no details. Would love to find out the reason.

Thanks!

[SanfordWhiteman · Accepted solution]

No issues, save for being unable to browse for assets (sometimes this ​is ​a big issue). The tracking pixel will still be Marketo's own.

I recommend you host over http​s:// (this can alleviate issues with webmail image proxies).

[Anonymous]

Thanks Sanford Whiteman

Just to make sure, do you know if this negatively affects an email's spam score:

Wanting to make sure having our emails sent from blah@xyz.com, having our links be links.xyzinsights.com (our marketo domain is a slightly different domain than our email addresses) and our image links being on xyz.cloudfront.net won't negatively affect our sender score or anything like that.

Any insight into this?

Thanks in advance.

[SanfordWhiteman]

Though serving images via CDN is in no way spammy, you might as well create images.xyzinsights.com pointing to your CloudFront distribution. It takes only a sec to set up, can't hurt and will certainly be easier to remember.

[Anonymous]

Thanks!

We actually do have that setup already but I noticed engineering still used the direct cloudfront links in the marketo emails.

I've always been curious whether our emails and link/images being two different domains affects how spam filters parse our emails.

[SanfordWhiteman]

It's vanishingly unlikely that the From: header domain not being present in your links has any effect on deliverability.

After all, unless you have the branded sender add-on to your Marketo subscription, the SMTP-level sender is @*.mktomail.com -- an explicit mismatch with domains that appear within the message content (most multitenant ESPs/MAPs have this same characteristic, it's not a Marketo thing).

What's critically important from a DNS standpoint is that you pass DKIM, confirming ownership and non-repudiation. That is, the operator of the domain in your From: has specifically authorized you to use it in emails (and, conversely, you can't claim that your emails are not legitimately tied to that domain).

[Anonymous]

That makes sense!

Thanks Sanford! Fell into a rabbit hole of reading your blog posts and finally emerged.

[SanfordWhiteman]

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