8-bit sending for Thunderbird Android

[ehyoitsdavid]

Currently when I send messages containing non-ASCII characters such as 中文 or emojis like 😡, even when the receiving server clearly supports 8BITMIME, the Thunderbird Android client downgrades them to quoted-printable encoding. This results in unnecessarily bloated message bodies, reduced readability in plain-text views, and a generally less efficient email experience.

It would be a meaningful improvement if Thunderbird Android could make use of 8-bit content transfer encoding when:

• The SMTP server advertises 8BITMIME in the EHLO response
• The message contains UTF-8 characters
• No user or policy explicitly forces quoted-printable

Adopting 8-bit encoding when it’s safe and supported would:

• Reduce message size (especially for languages like Chinese, Japanese, etc.)
• Improve clarity in plain-text views
• Align better with modern email standards and server capabilities

Ideally, this behavior could be toggled in settings, e.g., via a “Prefer 8 bit encoding when supported” option under composition or account preferences.

Thanks for considering this enhancement—it would go a long way toward making Thunderbird even more capable for global and emoji-rich communication.

[Jon]

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