Unable to open email attachments, .eml files

[kkimani]

When users attach an email from their inbox after composing a new email, they are not opening. In better terms, if I write a new email to a user in my domain, then attach a previous email I got, it doesnt open while in Ajax but in HTML it opens. Users dont want to use HTML format for the emails.

I'm using zimbra 8.8.15, upgraded it from zimbra 8.8.11 and still they where not opening. Before the upgrade to zimbra 8.8.11, I had zimbra 7 and the email attachments were opening.

I'm getting an error of a csfrToken and have tried to disable it but a SOAP error comes up and users cant login into their email accounts.