Attachments on FollowUp tickets

[numri]

Hello! We've just installed OTRS 3.1.10 and we're having some trouble with the attachments. (using POP3S)

If I send a new e-mail to OTRS with an attachment the mail is picked up correctly by OTRS with the attachment, however If I send a follow up e-mail to an already opened ticket with an attachment the mail is picked up by OTRS without the attachment.

Looking in the inbox before OTRS picks the mail up I can confirm that the attachment is still there.

Another peculiar thing is that if I manually select "Fetch Mail" directly after sending the mail to OTRS it fetches the same mail twice (once again without the attachment.)

Any idea what could be going on?