Plain text emails with unexpected line breaks

[Anonymous]

We're having a weird issue that I can't find discussion of... when we create plain text versions of our HTML email, they are sometimes displaying with strange mid-line breaks near the tops of paragraphs. These don't show up in the editor, they don't show up when I send myself tests, but other users are seeing them in the test versions.

When this happens, what should be

Here is the great call to action to make you click through to our landing page

becomes

Here is the
great call to action to make you click through to our landing page

This happens even if the plain text content is copied over from a plain text document, an RTF document, or with the Marketo copy from HTML feature. And there isn't any commonality in the email clients used to those seeing the breaks - in today's case, both I and the person seeing the breaks are using current versions of Outlook 2011 for Mac, the other day it was someone using Outlook 2013 on Windows.

So we're totally mystified.

[Josh_Perry1]

That is really wierd.  Have you contacted support?  They mght be able to help you.  I have never seen this happen. 

[Anonymous]

So, it gets weirder! We did some testing today to try to isolate the specific circumstances and here's what we found: the line break issue only appears when you generate a test message, and then send that attachment as a message using Outlook 2011 (Mac). Once you do that, the line breaks are messed up in the attached test message whether the recipient is viewing them on a Mac or Windows machine. Very, very strange.

But, the actual test messages look fine when they arrive from Marketo, if you just forward (vs. attaching the message to a new email, which I do often so that I can send text & HTML versions for review in one email), they look absolutely fine.

So the good news is we discovered that our actual messages coming from Marketo are formatted correctly. Which is good, because I couldn't figure out how a plain text message was developing weird extra line breaks only viewable in certain circumstances.

Problem solves. But... weird.