MOZ_LOG             POP3:5,timestamp
    MOZ_LOG_FILE    c:\Users\userid\Desktop\pop3.log

     pop3.log.moz_log

    c:\Users\Userid\Desktop> head -1 pop3.201227.log | wc
           1      12 550052793

    c:\Users\Userid\Desktop> head -2 pop3.201227.log | wc
          2      25 550052897

     tr '\000' '\040' < pop3.log.moz_log | tail +2 > pop3.201227.log

I am running with the debug environmental variable that produces a pop3.log file: MOZ_LOG POP3:5,timestamp MOZ_LOG_FILE c:\Users\userid\Desktop\pop3.log First, I noticed that in a recent update the log file name has changed to pop3.log.moz_log I am not sure why, as I told Mozilla what filename I wanted. But this is minor. The major problem is that the log file contains non-printable characters, and these characters make the file appear to the Unix Utilities on Windows (GOW [Gnu On Windows]) as a binary file. Before I process the file I have to translate null characters to blanks. This used to work to make the file appear as a character/text file. But now, there is a long, non-printable string of characters at the beginning of the file; I have to remove this first line to make GOW be able to process this file. Here is an example for a file that I have renamed and processed: c:\Users\Userid\Desktop> head -1 pop3.201227.log | wc 1 12 550052793 c:\Users\Userid\Desktop> head -2 pop3.201227.log | wc 2 25 550052897 The first "line" has 1 line, 12 "words" and 550M characters. The second line has 13 "words" and 104 characters. Why is Thunderbird writing a line with 550,052,793 characters? To process the file, I have to use the command: tr '\000' '\040' < pop3.log.moz_log | tail +2 > pop3.201227.log Why is Thunderbird writing this first long line, and can that line be omitted from the log? I am assuming that the null (x'00') characters I convert to blanks are all in this first line. Thanks. Thunderbird 78.6.0 (32-bit) on Windows 10 Professional 2004