We getting ready to role out roundcube for our webmail platform and our testing ran into one issue so far that seems like a good idea to push upstream. I searched but didn't find any mention of this so please pardon in advance if this has already been discussed.
One of our testers had an email with a pdf attachment that had a mime type of text/plain. Roundcube displays the pdf as text. We tested a few other clients and it looks like recent version of outlook and apple mail display the attachment as a pdf but thunderbird displays it as plain text so there isn't unanimous that a mail client should handle this either way.
What is roundcubes opinion on attachments with incorrect mime types? There's a pretty good argument that a end user doesn't really care that whoever sent them an attachment used broken software to do it, particularly if they use another client that displays it correctly.