Attaching Files to email and Calendar Events.
This is a summary of the original detailed article at https://wiki.illinois.edu/wiki/pages/viewpage.action?pageId=553980671
The Campus Mailing List server does not impose restrictions on attachment types. However, there is a maximum 10MB total message size limit. Keep in mind this setting defines the total "message size" which represents the message header (to/from, etc), the body(message) and any attachments. All attachments are translated to MIME which can more than double the size of a binary file. For example, the MIME conversion of a 5MB jpg becomes a +10MB MIME-attachment which exceeds the max message size. To work-around the 10MB limit subscribers can:
Reduce the size of their attached files to something that is more compatible with MIME. A total attachments around 4MB should be safe but each binary format expands into different MIME sizes.
Many customers have noticed calendar events behave differently from other attachments. The Campus Mailing List Server is simply passing the attachment as any other attachments and does not manipulate the data or rename the file. However, each email client (Outlook, GMail, Yahoo, Hotmail, etc..) independently defines how they choose to handle the calendar event. We've notice different behaviors when you "create a calendar event" and invite a list to the event vs. "drag-n-dropping a calendar event" to an email and send it to a list.
In summary, there are a few options for sending calendar events to a mail list:
Option 1) Best: To make sure your invite makes it to "all" the subscribers on your list, regardless of which email client they use, we recommend you add the event information to the body of the message. This will ensure your subscribers receive the relevant information and they can create the appropriate event on their calendar. + option 2 for those user's whose email client will provide the add to calendar options.
Option 2) Add the mail list address to the invitee list for the event and most email clients will allow the user to interact with the data. Most email clients not all....
Worse: drag-n-drop a calendar event to an email that you're sending to
a mail list. In this case, most email clients see the attachment as
suspect and will rename it, delete it or provide an ascii version of the
information in a text file.