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<p dir="auto">Hi,</p>
<p dir="auto">I went down a rabbit hole last week and implemented some basic support for removing certain strings from HTML and plain text when creating a reply (or forwarding) a message. I'm unlikely to do more with this feature right now (spent more time on it than I should), but I wanted to share it in case it's useful for anyone in its current state (other than the individual asking me about it). Maybe also to get some more use cases to better generalize it (some day -- not now).</p>
<p dir="auto">A user had the problem that most of his replies would contain this: "External Message: Use Caution". When HTML was involved, it would be embedded in the original HTML. Its purpose, I assume, is to make a user aware whenever an email is received from outside an organization. I won't go into whether or not I think this is a good idea, but it's a problem that this text then goes into the reply as well. In particular for HTML which cannot be edited in MailMate without converting it to plain text.</p>
<p dir="auto">In any case, it would be nice if it could be automatically removed, but this turned out to be non-trivial. Well, for plain text, it was fairly simple and it could be configured like this:</p>
<pre style="margin-left: 15px; margin-right: 15px; padding: 5px; background-color: #F7F7F7; border-radius: 5px 5px 5px 5px; overflow-x: auto; max-width: 90vw;"><code style="margin: 0 0; border-radius: 3px; background-color: #F7F7F7; padding: 0px;">defaults write com.freron.MailMate MmPlainTextStrippingRegexps \
-array "^External Message: Use Caution"
</code></pre>
<p dir="auto">For HTML, I tried to make it simple by only requiring the user to provide the inner-most part of the HTML and then MailMate would extend it to whatever makes sense. In this particular case, I still ended up with this:</p>
<pre style="margin-left: 15px; margin-right: 15px; padding: 5px; background-color: #F7F7F7; border-radius: 5px 5px 5px 5px; overflow-x: auto; max-width: 90vw;"><code style="margin: 0 0; border-radius: 3px; background-color: #F7F7F7; padding: 0px;">defaults write com.freron.MailMate MmHTMLStrippingRegexps
-array '"<span [^>]*>External Message:</span> Use Caution"' \
'"<td style=\"background:#ff0000;padding:5pt 2pt 5pt 2pt\"></td>"'
</code></pre>
<p dir="auto">The second string was to get rid of a red bar. It's not very intuitive and hard to configure.</p>
<p dir="auto">Note that for an HTML email, both of the above settings are needed since text still needs to be removed from the plain text alternative (which in MailMate can be seen in the text editor part of the composer).</p>
<p dir="auto">The full HTML (automatically removed by MailMate using the above) looked like this:</p>
<pre class="highlighted" style="margin-left: 15px; margin-right: 15px; padding: 5px; background-color: #F7F7F7; border-radius: 5px 5px 5px 5px; overflow-x: auto; max-width: 90vw; color: black;"><code style="margin: 0 0; border-radius: 3px; background-color: #F7F7F7; padding: 0px;"><span class="token tag" style="color: #905;"><span class="token tag" style="color: #905;"><span class="token punctuation" style="color: #999;"><</span>table</span> <span class="token attr-name" style="color: #690;">border</span><span class="token attr-value" style="color: #07a;"><span class="token punctuation attr-equals" style="color: #999;">=</span><span class="token punctuation" style="color: #999;">"</span>0<span class="token punctuation" style="color: #999;">"</span></span> <span class="token attr-name" style="color: #690;">cellspacing</span><span class="token attr-value" style="color: #07a;"><span class="token punctuation attr-equals" style="color: #999;">=</span><span class="token punctuation" style="color: #999;">"</span>0<span class="token punctuation" style="color: #999;">"</span></span> <span class="token attr-name" style="color: #690;">cellpadding</span><span class="token attr-value" style="color: #07a;"><span class="token punctuation attr-equals" style="color: #999;">=</span><span class="token punctuation" style="color: #999;">"</span>0<span class="token punctuation" style="color: #999;">"</span></span> <span class="token attr-name" style="color: #690;">align</span><span class="token attr-value" style="color: #07a;"><span class="token punctuation attr-equals" style="color: #999;">=</span><span class="token punctuation" style="color: #999;">"</span>left<span class="token punctuation" style="color: #999;">"</span></span> <span class="token attr-name" style="color: #690;">width</span><span class="token attr-value" style="color: #07a;"><span class="token punctuation attr-equals" style="color: #999;">=</span><span class="token punctuation" style="color: #999;">"</span>100%<span class="token punctuation" style="color: #999;">"</span></span><span class="token punctuation" style="color: #999;">></span></span>
<span class="token tag" style="color: #905;"><span class="token tag" style="color: #905;"><span class="token punctuation" style="color: #999;"><</span>tbody</span><span class="token punctuation" style="color: #999;">></span></span>
<span class="token tag" style="color: #905;"><span class="token tag" style="color: #905;"><span class="token punctuation" style="color: #999;"><</span>tr</span><span class="token punctuation" style="color: #999;">></span></span>
<span class="token tag" style="color: #905;"><span class="token tag" style="color: #905;"><span class="token punctuation" style="color: #999;"><</span>td</span> <span class="token attr-name" style="color: #690;">style</span><span class="token attr-value" style="color: #07a;"><span class="token punctuation attr-equals" style="color: #999;">=</span><span class="token punctuation" style="color: #999;">"</span>background:#ff0000;padding:5pt 2pt 5pt 2pt<span class="token punctuation" style="color: #999;">"</span></span><span class="token punctuation" style="color: #999;">></span></span><span class="token tag" style="color: #905;"><span class="token tag" style="color: #905;"><span class="token punctuation" style="color: #999;"></</span>td</span><span class="token punctuation" style="color: #999;">></span></span>
<span class="token tag" style="color: #905;"><span class="token tag" style="color: #905;"><span class="token punctuation" style="color: #999;"><</span>td</span> <span class="token attr-name" style="color: #690;">width</span><span class="token attr-value" style="color: #07a;"><span class="token punctuation attr-equals" style="color: #999;">=</span><span class="token punctuation" style="color: #999;">"</span>100%<span class="token punctuation" style="color: #999;">"</span></span> <span class="token attr-name" style="color: #690;">cellpadding</span><span class="token attr-value" style="color: #07a;"><span class="token punctuation attr-equals" style="color: #999;">=</span><span class="token punctuation" style="color: #999;">"</span>7px 6px 7px 15px<span class="token punctuation" style="color: #999;">"</span></span> <span class="token attr-name" style="color: #690;">style</span><span class="token attr-value" style="color: #07a;"><span class="token punctuation attr-equals" style="color: #999;">=</span><span class="token punctuation" style="color: #999;">"</span>background:#ff000;padding:5pt 4pt 5pt 12pt;word-wrap:break-word<span class="token punctuation" style="color: #999;">"</span></span><span class="token punctuation" style="color: #999;">></span></span>
<span class="token tag" style="color: #905;"><span class="token tag" style="color: #905;"><span class="token punctuation" style="color: #999;"><</span>div</span> <span class="token attr-name" style="color: #690;">style</span><span class="token attr-value" style="color: #07a;"><span class="token punctuation attr-equals" style="color: #999;">=</span><span class="token punctuation" style="color: #999;">"</span>color:#000000;<span class="token punctuation" style="color: #999;">"</span></span><span class="token punctuation" style="color: #999;">></span></span><span class="token tag" style="color: #905;"><span class="token tag" style="color: #905;"><span class="token punctuation" style="color: #999;"><</span>span</span> <span class="token attr-name" style="color: #690;">style</span><span class="token attr-value" style="color: #07a;"><span class="token punctuation attr-equals" style="color: #999;">=</span><span class="token punctuation" style="color: #999;">"</span>color:#000000; font-weight:bold;<span class="token punctuation" style="color: #999;">"</span></span><span class="token punctuation" style="color: #999;">></span></span>External Message:<span class="token tag" style="color: #905;"><span class="token tag" style="color: #905;"><span class="token punctuation" style="color: #999;"></</span>span</span><span class="token punctuation" style="color: #999;">></span></span> Use Caution
<span class="token tag" style="color: #905;"><span class="token tag" style="color: #905;"><span class="token punctuation" style="color: #999;"></</span>div</span><span class="token punctuation" style="color: #999;">></span></span>
<span class="token tag" style="color: #905;"><span class="token tag" style="color: #905;"><span class="token punctuation" style="color: #999;"></</span>td</span><span class="token punctuation" style="color: #999;">></span></span>
<span class="token tag" style="color: #905;"><span class="token tag" style="color: #905;"><span class="token punctuation" style="color: #999;"></</span>tr</span><span class="token punctuation" style="color: #999;">></span></span>
<span class="token tag" style="color: #905;"><span class="token tag" style="color: #905;"><span class="token punctuation" style="color: #999;"></</span>tbody</span><span class="token punctuation" style="color: #999;">></span></span>
<span class="token tag" style="color: #905;"><span class="token tag" style="color: #905;"><span class="token punctuation" style="color: #999;"></</span>table</span><span class="token punctuation" style="color: #999;">></span></span>
<span class="token tag" style="color: #905;"><span class="token tag" style="color: #905;"><span class="token punctuation" style="color: #999;"><</span>br</span><span class="token punctuation" style="color: #999;">></span></span>
</code></pre>
<p dir="auto">After hinting this feature in the release notes, several users asked about it and I got some more examples. These show a lot of variation and it's tricky to come up with an approach that would work well in general. Some of them were a lot worse than the above. I ended up with these settings:</p>
<pre style="margin-left: 15px; margin-right: 15px; padding: 5px; background-color: #F7F7F7; border-radius: 5px 5px 5px 5px; overflow-x: auto; max-width: 90vw;"><code style="margin: 0 0; border-radius: 3px; background-color: #F7F7F7; padding: 0px;">defaults write com.freron.MailMate MmPlainTextStrippingRegexps \
-array '\\AThis email was sent to you by someone outside the University.\\nYou should only click on links or attachments if you are certain that the email is genuine and the content is safe.\\n' \
'"\\AYou don.t often get email from[^<]*<https://aka.ms/LearnAboutSenderIdentification>\\nCaution: This email originated from outside of the organization. Please take care when clicking links or opening attachments. When in doubt, contact the ICT Department.\\n"' \
'\\AExternal Message: Use Caution\\n'
defaults write com.freron.MailMate MmHTMLStrippingRegexps \
-array '"(?m)^<div style=\"background-color:#fff2e6; border:2px dotted #ff884d\">.*?^</div>\\n"' \
'"(?m)^<!-- Red Banner -->\\n<table.*</table>\\n<br>\\n"' \
'"(?m)<table[^>]*>.*?(You don.t often get email from|This email originated from outside of the organization).*?</table>"' \
'"(?m)^<!-- BaNnErBlUrFlE-BoDy-start -->\\n.*?^<!-- BaNnErBlUrFlE-BoDy-end -->\\n"'
</code></pre>
<p dir="auto">Most users would, of course, only need to handle 1 variation of this.</p>
<p dir="auto">This feature is highly experimental in the sense that I'm not even promising to fix it if it's broken ;) I'm more likely to implement it in a different way.</p>
<p dir="auto">Hold down ⌥ when clicking “Check Now” in the Software Update settings pane to get the latest test release. The above works in r6220+.</p>
<p dir="auto">While looking at one of the examples above, I also realized that at least one of these embedded-warning techniques could introduce a potential privacy-issue... I'll have to investigate that a bit more though.</p>
<p dir="auto">--<br>
Benny<br>
<a href="https://freron.com/support" style="color: #3983C4;">https://freron.com/support</a></p>
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