I can't see attachment file

[UltimoTangoAparigi]

Did you received my mail which I sent last week ?

[prashant]

I could not reproduce issue on my system after injecting the mime you provided.Sent you the mail for the same.

[UltimoTangoAparigi]

Thanks for your help, now I can say problem is on my Zimbra server.
I have main mail server (A) which runs a sendmail instance. This mail server forwards email to Zimbra (Z).

I asked to the specific sender to send same mail to address:
- for a mailbox on server A
- for a mailbox on server Z

on server A this msg is OK
on server Z has the same problem

What can I check on advanced options in my account ?
what I have to set for:

attachments must be visible in original format or HTML format ? both ?

[UltimoTangoAparigi]

I could not reproduce issue on my system after injecting the mime you provided.Sent you the mail for the same.

After very long long tests, perhaps I found out the problem in Zimbra, infact this one cannot decode base64 attachments. Did you have experience about it ?

I read these articles:

Zimlet cookbook based on JavaScript API - Zimbra :: Wiki

and

the thread called "zimlet for decoding base64-encoded attachments" into section "Zimbra Collaboration Suite > Zimlets" , written by gray03.

what do you think ?