QuoteAndComposeManager works in TB 60, including the chevron removal, but you have to open Edit/Preferences(Windows:Tools/Options)/Advanced/General/Config. editor and double-click the preference extensions.strictCompatibility to false, OK to close Preferences.

There's also a 'cleanup the quote character >' option in ReplyWithHeader.

Thanks for responding.

I managed to install QuoteAndComposeManager but it didn't have any effect while composing in HTML. It only works in plain text format!

Also the ReplyWithHeader "clean up the quote character" doesn't remove the chevrons either.

In fact, the chevrons possibly prevent Thunderbird displaying the original quoted message as HTML in my reply - I'm testing it by sending myself loads of emails :) but basically my reply looks like HTML before I send it, but when it arrives, I see all the chevrons and no HTML.

So problem half-solved, at least for plain text format. So I'll switch across to that. However it would be nice to be able to reply with HTML in the quoted email.

re: but basically my reply looks like HTML before I send it, but when it arrives, I see all the chevrons and no HTML. Sounds like you might be writing in HTML but sending as Plain Text. Menu icon > options > Options > Composition > 'General' tab click on 'send options' button. Select: 'Send the message in both plain text and HTML'

click on OK

Well that was a strange one.

In the global general "Send Options", where it says "when sending messages in HTML format and one or more recipients are not listed as being able to receive HTML", I had the dropdown set to "Convert HTML to plain text".

So in my test, I replied to an HTML email, the compose window showed HTML, but sending it to myself, TB obviously converted it to plain text and that's the point where the chevrons were inserted.

By changing it to "both plain text and HTML" , it solved the issue.

Seems that the 2 plugins don't get invoked when sending converts the HTML to plain text, and it's at that point that the chevrons are inserted.

I guess it's not ideal, but it's not really a bug.

I'd say TB has an issue - not allowing any options regarding chevrons as indent markers is a bit rigid.

The recipient in my tests was always myself.

re :By changing it to "both plain text and HTML" , it solved the issue. good to hear all is ok. Could you mark my previous comment suggesting you made that change as 'Chosen solution' so that others with similar issue can locate a solution. Thanks.

OK, there you go, but I did hesitate because it's not actually solved the issues - (1) that TB won't allow us to get rid of the chevrons natively and (2) the plugins don't handle the situation with the chevrons when TB converts the email from HTML to plain text on sending.

Check settings: Menu icon > Options > Options > Advanced > General tab click on 'Config Editor' button I've viewed my emails as plain text and can convert chevrons to coloured vertical lines using the following values. In search type: quote mail.quoted_graphical set value as True mail.quoteasablock set value as False. double click on line will toggle the value.

But chevrons are in the source code. This is conventional method used by email interfaces when sending replies with inline text as mentioned in RFC3676.

re :I've already implemented the chrome/userContent.css and user.js changes, but that just hides the chevron via HTML & CSS in the most recent email, and

I presume you mean inserting css for the blockquote settings with 0 values. Yes this works very well to remove lines etc.

To all intents and purposes there are a few ways of altering how you prefer to read/view your emails. This ability to tweak preferences is one of the reasons why I prefer Thunderbird.

But it does not remove how the email is constructed in the source code. There are conventions and rules that need to be adhered to, so emails can be sent and received by various systems, programs etc etc and still be understood; like a common language. see: https://www.ietf.org/rfc/rfc3676.txt