Newsletter not rendered properly when send through scheduler

Dear reader,

We send out a newsletter once every month and 3 months ago we first noticed that when we received the newsletter as is was send through the scheduler was not rendered properly. We viewed the newsletter in both Apple Mail on iOS, MacOs and Outlook 2016 for Mac.

For this month we completely rebuild our template from scratch and created a fresh newsletter. Sending an example convinced us that the rendering issues where solved.

Unfortunately this morning when we received the newsletter once again the lay-out was all messed up.

Created a new newsletter based on one of the standard templates (Birds / Ornithology) to verify once more if the issue lay in our template. This newsletter (template with no changes to content) was also send out with the lay-out messed up. Sending an example from the editor also resulted in a messed up layout. The trick in this template was tot remove the social media buttons. After that change that “newsletter” was send and received properly.

Next I created a copy of our newsletter in order to send a test mail from within the editor. To my surprise this newsletter displayed properly in all mail clients we have (see above). So i scheduled this newsletter to be send out and stopped the sending of the earlier newsletter.

But then when I received the newsletter, once again the layout was all messed-up
🙁

Screenshot 1 Proper layout when send as example

Screenshot 2 Messed-up layout when send through scheduler

I hope you can help solve this issue.

Thanks in advance,
Jeroen