Kolab discards attachment (Roundcube)

[Jens Lüttgens]

Hello folks,

I wrote an e-mail using the web interface and a pdf file.

Upon sending the mail, the attachment was stripped from the mail so that 
the recipient got the mail but without any attachments.
When I tried to send the file again, the very same thing happend 
reproducibly all over again (and left me look like a complete idiot...).

What do I need to do to help fix this so it doesn't happen again? 
Unfortunately however, the pdf is of somewhat personal nature and 
includes some sensitive information so that I cannot attach it here.

Kind regards,

Jens