BUG: Trouble viewing PostMark messages in HTML.
Posted: Thu Jan 26, 2023 11:42 am
When reviewing emails in Mailwasher (v 7.12.97), that were received from https://postmarkapp.com, I noticed that they cannot be viewed in HTML. My company uses https://postmarkapp.com for all transactional emails, in HTML format, and not being able to view them is a big problem for me.
I can see the plain text version, but when I try to view the HTML version I get this message:
This is a bug in Mailwasher, as I will explain below. Would it be possible for Firetrust to repair this bug in Mailwasher?
EXPLANATION:
The emails are shown correctly in the Outlook and Thunderbird clients on Windows 11, and I can see the HTML of emails from other sources in Mailwasher. There's something special about the way PostMark uses the multipart MIME format that trips up Mailwasher.
Below is an example of an email message. This is the raw source with the top-most receive/delivered headers removed and the email addresses changed. I took care to keep the empty lines exactly as they were.
I've ran some tests, and the conclusion is that the problem is the Content-Type header. This header doesn't work in Mailwasher:
Whereas this one does:
This is clearly a bug in the way Mailwashes handles the Content-Type header, it should take note of the semi-column separator.
The source for this is RFC 2045 section 5.1:
https://www.rfc-editor.org/rfc/rfc2045#section-5.1.
The special characters are: ()<>@,;:\"/[]?=.
I can see the plain text version, but when I try to view the HTML version I get this message:
- noHTML.png (5.21 KiB) Viewed 5941 times
This is a bug in Mailwasher, as I will explain below. Would it be possible for Firetrust to repair this bug in Mailwasher?
EXPLANATION:
The emails are shown correctly in the Outlook and Thunderbird clients on Windows 11, and I can see the HTML of emails from other sources in Mailwasher. There's something special about the way PostMark uses the multipart MIME format that trips up Mailwasher.
Below is an example of an email message. This is the raw source with the top-most receive/delivered headers removed and the email addresses changed. I took care to keep the empty lines exactly as they were.
Code: Select all
From: [email protected]
Date: Fri, 30 Dec 2022 18:36:12 +0000
Subject: Hello from Postmark!
Message-Id: <[email protected]>
To: [email protected]
Feedback-ID: s9356667-_:s9356667:a142788:postmark
X-Complaints-To: [email protected]
X-PM-Message-Id: 3fbdfb17-ea98-4f19-bf90-b763aad3c7fd
X-PM-RCPT: |bTB8MTQyNzg4fDkzNTY2Njd8d3BkZWpvbmdAdC1tb2JpbGV0aHVpcy5ubA==|
X-PM-Message-Options: v1;9Hcc_PIAriBnYBOfaIwCcyIPcaJJ4QcTBG0Vjf0upsKfpR9qOJtFHrXwPywaBTAW0yivONdmCE8g_Gy1UcqUBBDOwW7mU_BYoMQKRhXnXR0
MIME-Version: 1.0
X-PM-MTA-Pool: transactional-3
Content-Type: multipart/alternative;
boundary=mk3-470f5c3c4d4c47aebbab1dbc28d62e07; charset=UTF-8
--mk3-470f5c3c4d4c47aebbab1dbc28d62e07
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
This is just a friendly 'hello' from your friends at Postmark.
--mk3-470f5c3c4d4c47aebbab1dbc28d62e07
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
This is just a friendly <i>'hello'</i> from your friends at Postmark.
--mk3-470f5c3c4d4c47aebbab1dbc28d62e07--
I've ran some tests, and the conclusion is that the problem is the Content-Type header. This header doesn't work in Mailwasher:
Code: Select all
Content-Type: multipart/alternative;
boundary=mk3-470f5c3c4d4c47aebbab1dbc28d62e07; charset=UTF-8Whereas this one does:
Code: Select all
Content-Type: multipart/alternative;
boundary=mk3-470f5c3c4d4c47aebbab1dbc28d62e07This is clearly a bug in the way Mailwashes handles the Content-Type header, it should take note of the semi-column separator.
The source for this is RFC 2045 section 5.1:
https://www.rfc-editor.org/rfc/rfc2045#section-5.1.
The special characters are: ()<>@,;:\"/[]?=.