Whenever a client of mine sends out attachments they keep turning into winmail.dat files. However, if I send one to my exchange account or gmail they seem fine. However, if they send to their e-mail which is an internet firstname.lastname@example.org they get the winmail.dat instead of an attachment.
The emails go out as HTML as I have seen in the settings and the profile was recreated to remove all possible culprits so that they operate at default settings.
Here is the view-source of the email. It looks like it is in HTML: (viewing from outlook 2013 on my end at one of their emails)
<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head> <meta http-equiv="Content-Type" content="text/html; charset=us-ascii"> <meta name="Generator" content="Microsoft Word 15 (filtered medium)">
><!--[if gte mso 9]><xml> <o:shapedefaults v:ext="edit" spidmax="1026" /> </xml><![endif]--><!--[if gte mso 9]><xml> <o:shapelayout v:ext="edit"> <o:idmap v:ext="edit" data="1" /> </o:shapelayout></xml><![endif]--> </head>
Other ideas on how to debug this issue?