We are attaching build log to the mail in Jenkins pipeline, and are setting both "attachLog" and "compressLog" options to true. The build logs say "Skipping build log attachment - too large for maximum attachments size".
When downloading the logs manually, these are about 40 MB in size (uncompressed) and less than 3 MB compressed. The "Maximum Attachment Size" is set to 16 MB on global setting page, so the compressed log should pass in any case.
It seem the plugin is comparing size of uncompressed logs with the given limit, which is not what I would expect.