How To Email & Messaging Log POP, IMAP, and SMTP Traffic in Mozilla Thunderbird Share Pin Email Print Email & Messaging Tips & Tricks Gmail Tips & Tricks Yahoo Tips & Tricks Outlook Tips & Tricks Basics Guides & Tutorials Installing & Upgrading Key Concepts VoIP by Heinz Tschabitscher Updated November 14, 2017 Logging POP, IMAP, and SMTP email traffic isn't just for the industrious developer. If you want to see what's going on behind the scenes of your email exchanges in Mozilla Thunderbird (especially if what's going on is not going right), logging can yield lots of information that can help you or your tech support person diagnose the problem.Turning On Transaction LoggingTurning on transaction logging may not be a straightforward affair, but it is not difficult, either. To create a log file with all POP (Post Office Protocol), SMTP (Simple Mail Transfer Protocol), and IMAP (Internet Message Access Protocol) traffic in Mozilla Thunderbird, first make sure it's not running. Then, follow the instructions for your operating system.In Windows Select All Programs | Accessories | Command Prompt from the Start menu.Type set NSPR_LOG_MODULES= followed immediately by:POP3:4 for POP loggingIMAP:4 for IMAP loggingSMTP:4 for SMTP loggingYou can enable logging for multiple protocols by separating them with commas. For example:To log both POP and SMTP traffic, type set NSPR_LOG_MODULES=POP3:4,SMTP:4.To log only IMAP traffic, type set NSPR_LOG_MODULES=IMAP:4.Press Enter.Type set NSPR_LOG_FILE=%HOMEDRIVE%%HOMEPATH%\Desktop\tbird_log.txt.Press Enter.Type start thunderbird.Press Enter again.Perform the desired email actions in Mozilla Thunderbird.Quit Mozilla Thunderbird and find tbird_log.txt on your Desktop. In Mac OS XOpen a Terminal window.Type export NSPR_LOG_MODULES= followed immediately by:POP3:4 for POP loggingIMAP:4 for IMAP loggingSMTP:4 for SMTP loggingPress Enter.You can enable logging for multiple protocols by separating them with commas. For example:To log both POP and SMTP traffic, type export NSPR_LOG_MODULES=POP3:4,SMTP:4.To log only IMAP traffic, type export NSPR_LOG_MODULES=IMAP:4. Type export NSPR_LOG_FILE=~/Desktop/tbird.log.Press Enter.Type /Applications/Thunderbird.app/Contents/MacOS/thunderbird-bin.Press Enter again.Perform the desired email actions in Mozilla Thunderbird.Quit Mozilla Thunderbird and find tbird.log on your Desktop.On Linux:Open a Terminal window.Type export NSPR_LOG_MODULES= followed immediately by:POP3:4 for POP loggingIMAP:4 for IMAP loggingSMTP:4 for SMTP loggingPress Enter. You can enable logging for multiple protocols by separating them with commas. For example, type:export NSPR_LOG_MODULES=POP3:4,SMTP:4 to log both POP and SMTP trafficexport NSPR_LOG_MODULES=IMAP:4 to log only IMAP trafficType export NSPR_LOG_FILE=~/tbird.log.txt.Press Enter.Type thunderbird.Press Enter again.Perform the desired email actions in Mozilla Thunderbird.Quit Mozilla Thunderbird and find tbird.log.txt in your Home directory.Turn Logging Off in Mozilla ThunderbirdTraffic logging is enabled only for the session you start from the command line. You do not have to turn it off. Was this page helpful? Thanks for letting us know! Share Pin Email Tell us why! Other Not enough details Hard to understand Submit Continue Reading