[Alpine-info] Test mail to "Forwarded mail partially invisible in Outlook"

[Andreas Schamanek]

On Sun, 18 Feb 2024, at 13:17, Olaf Skibbe wrote:


> A problem was that I could not provide complete e-mails here, as their

> content was confidential. I now succeeded to construct the problem

> "from scratch": (...)


Great work! Thanks to the samples you attached I was able to reproduce 
your findings, including the keyword "boundary" in all caps. Contrary 
to what I boldly claimed in my previous message it's indeed in the 
source code. I stand corrected. Alpine sometimes uses "boundary", at 
other times "BOUNDARY".


> The question I would like to address here, is whether alpine is

> behaving standard compliant or not. If not, we have a bug in alpine.


I wonder how to validate the MIME structure of a message. I guess 
there are tools but I don't know of any.

I'd say Alpine is behaving correctly, especially in the sense that in 
your case (the message generated by OWA) it does not modify what it 
forwards, and it wraps it properly AFAICS.

Also, all programs I have at hand (Alpine, Mutt, Thunderbird, Perl's 
Email::MIME) are dealing just fine with it, with only Thunderbird 
behaving slightly different (see below).


> 1. I composed a mail in the outlook web interface (OWA). To show the

>   problematic behavior it has to have all of the following

>   properties:

>   - It has to be HTML format,

>   - it has to have an inline picture,

>   - it has to have an attachment.


I must say I have had to deal with issues with more complicated 
messages in the past. Not often, but I do remember that people 
complained about not being able to see or open parts of messages.


> 4. In OWA, the text of the forwarded mail is not displayed, see

>   attached screenshot.


I sent my forwarded message to a test account @outlook.live.com which 
behaves like you described.

Interestingly, Thunderbird does also not show all content under all 
circumstances. My Thunderbird 115.7 on Ubuntu shows all content like 
Alpine if I use View -> Message Body As -> Simple HTML or Plain Text. 
When I switch to Original HTML the 2 paragraphs "Test using a HTML 
text. Again sent via OWA with attachment "test.pdf"" and "Inline 
picture included." are _not_ shown, only the picture is shown (which 
confusingly shows the same text; nice trick to test people's 
awareness;). This, I'd say, qualifies as a bug of Thunderbird.

(BTW: In Thunderbird, in the Plain Text view I cannot view the inline 
image. That might be known bug, though?)


> If alpine is doing fine (which I expect somehow), it seems to be an

> outlook bug.


I tried to tweak the source code of the message to see whether it 
would change Outlook's or Thunderbird's behavior. I tried

- removing the `TYPE="multipart/alternative"`
- removing the futile `multipart/related`
- removing all added `Content-ID` headers

Nothing changed.


> I am willing to bring the issue to the IT department of my 

> university, but they will probably not be able to solve this.


Probably. A number of my colleagues just try to explain the values of 
open source compared to offers by too big to block corporations. I 
feel like trapped in an epic saga, you know, the David versus Goliath 
kind. The level of entertainment is questionable, though.


> A workaround for me is to forward the whole mail as attachment by

> pressing H (full headers on) and then F.


This is what I do when I have to forward HTML. But since I usually 
stay away from HTML, I save the attachments, forward the plain text 
and re-add the attachments.

Hope that helps,

-- 
-- Andreas

      :-)