This is my first time on the forum so apologies if this has been covered before. Also to note I am not an email designer but rather a client trying to figure out an issue that has been going on for weeks. So my knowledge on the subject is very limited.
The company I work for recently signed a contract with a media monitoring provider that is required to send a daily email to a group of 50 people at my company.
It is a requirement that the HTML email template also has a PDF attached (news clipping for the day).
When the PDF is over about 500kb, the email renders as plain text on iPhones and iPads using Apple Mail. You then have to scroll to the bottom of the email and press “download remaining email”. This only happens when accessing the email on iPhones/Pads through the work email client, which is Microsoft Outlook (Office 365).
Other things to note:
It renders perfectly on iPhones/iPads when the PDF is smaller than 500kb (or when no PDF is attched)
It renders perfectly on iPhones/iPads when using a non-Microsoft client e.g my personal iiNet email account
It renders perfectly on iPhones/iPads when using a third party app e.g. the outlook app
It works on all other devices and the desktop - even when the PDF is larger than 500kb
So it appears to be an Office 365 issue to me. I would very much appreciate any feedback or advice so I can relay to my IT department.