I'm having a problem with some recipients being unable to access .htm attachment files.
There is no Exchange involved. Our MTA is Zimbra. Both clients are MS Outlook 2007.
The story goes like this.
1. Bob receives an email from the outside. It looks like a text/plain body with a .htm attachment.
2. Bob forwards the email to Joe.
3. Joe receives the email and can briefly see the .htm contents (not the text) in the outlook preview pane.
4. The clip icon briefly appears in Joe's inbox.
5. As Joe moves to the next message in his inbox, the .htm contents dissapears, so the clip icon.
6. Looking at Joe's inbox, it appears as he received an empty message. No body, no attachment.
7. We have tested this using Joe's webmail and the message seems complete. The .htm file appears as inline content.
I'm sending below some of the message headers. The Content... headers seem wrong to me. The original message was supposed to be a multipart. Message body begins with the <HTML> tag and is exactly the attached file.
Bob has the composing format selected as HTML, no RTF.
I haven't tested the level1remove yet.
Behavior is consistent with all messages with a .htm attachment. Sending other content types seems to work.
Joe uses POP3.
AV software might be involved. I'm yet to test around it.
I've already seen some previous threads and MS KB articles about this, but they mostly target RTF and Exchange tweaking, and no real soluion.
Thanks for any hint.
Subject: RV: o/c_MTS_Nro.82028154
Date: Wed, 5 Oct 2011 17:29:50 -0300
X-Mailer: Microsoft Office Outlook 12.0