2.6.0

New Features:

• Added "Substitute folding white spaces (FWS)" option for Thunderbird 128 Beta and later. Enabled by default to ensure compatibility with existing user configurations.

Behavior changes:

• In Thunderbird 128 Beta, headers unfolding behavior has been updated to retain folding white spaces (FWS) instead of substituting them with spaces as in previous Thunderbird versions.

2.5.3

• Remove unused load detection

2.5.2

• Add support for TB 111+

2.5.1

• Add negative header indices support. Negative indices count backwards from the bottom of the message.
• Improve single line mode headers separator. Now the arrow points in mail flow direction and the box is used as a separator for out-of-order sequences. The arrow has been replaced with a heavy arrow, so it is easier to spot in a long string of text.

2.4.3

• Fix multiple headers display on TB102+

2.4.2

• Restore copy popup on TB100+

2.4.1

• Hide Received header until its value is set
  to avoid showing header of the previous message during network/processing delay

2.4.0

• Add option to remove duplicate headers. Submitted by: @the-glu
• Add option to display all headers on a single line. Submitted by: @the-glu

2.3.3

• Just update strict_max_version

2.3.2

• Fix header display on TB 100.0+