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Thunderbird: How to disable message forwarding in base64

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  • 2 have this problem
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  • Last reply by Toad-Hall

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Apparently since the Update to Thunderbird 45, HTML-mails get forwarded as base64. Is there any way to disable this and go back to the former behavior without downgrading to 38.x?

For example:


User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101

Thunderbird/45.3.0

MIME-Version: 1.0 In-Reply-To: <...> Content-Type: multipart/alternative;

boundary="------------41543626587C7FD8D269B4D8"

This is a multi-part message in MIME format.


41543626587C7FD8D269B4D8

Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit

...Plaintext...


41543626587C7FD8D269B4D8

Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: base64

...HTML and attachements in base 64...


Apparently since the Update to Thunderbird 45, HTML-mails get forwarded as base64. Is there any way to disable this and go back to the former behavior without downgrading to 38.x? For example: -------------- User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <...> Content-Type: multipart/alternative; boundary="------------41543626587C7FD8D269B4D8" This is a multi-part message in MIME format. --------------41543626587C7FD8D269B4D8 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit ...Plaintext... --------------41543626587C7FD8D269B4D8 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: base64 ...HTML and attachements in base 64... --------------

Chosen solution

It would seem you located the answer before I got to this query. Thankyou for reporting back with info. could you mark your own response as 'Chosen Solution'.

As additional info, just in case someone else locates this same query. setting "mail.strictly_mime" to true is done via the 'Config editor' located here: 'Menu icon' > 'Options' > 'Options' >'Advanced' > 'General' tab click on 'Config Editor' button.

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All Replies (2)

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As it seems, setting "mail.strictly_mime" to true, solves my problem.

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Chosen Solution

It would seem you located the answer before I got to this query. Thankyou for reporting back with info. could you mark your own response as 'Chosen Solution'.

As additional info, just in case someone else locates this same query. setting "mail.strictly_mime" to true is done via the 'Config editor' located here: 'Menu icon' > 'Options' > 'Options' >'Advanced' > 'General' tab click on 'Config Editor' button.