[Mailman-Users] Images on iPhone's not loading

[James Nightly]

Our school newsletter often has a few images accompanying news
articles. These images load fine on android phones and in regular
computer browsers. Images do now show on the same message and email
account when viewed on iPhone's. On iPhone all I see is an outline of
an image with file name and none of the images load/show.
Articles/text loads fine.

filter_content is set to No
iPhone settings > Email > Load email images is enabled

We are on v. Mailman 1:2.1.18-1, Debian 3.16.3-2