Attachments to emails sent via ZohoCRM won't open

Attachments to emails sent via ZohoCRM won't open

Hello,
 
We've noticed when sending emails via ZohoCRM that in some rare cases the recipient cannot open the PDF attachments.
 
The pdf has a ; at the end of the name preventing the computer from automatically recognising it as a pdf.
 
We've tested this with various templates, different PDFs and sending the same PDF via Outlook and even SalesForce (from another business we work with).
 
Specifically this happens when sent from ZohoCRM to anyone using Goldmine to open their emails.
 
Is this a known issue? Are there any solutions?
 
Kenneth