Although the log file generated by procmail is a plain text file, RW4M displays it such that you can quickly sort the log entries. To retrieve the log file, from the Download menu select Log or click the corresponding button. Below is a screenshot of an open procmail log file.
Each log entry is displayed in one row. You can specify custom colors so that specific entries you're interested in will stand out. You can sort on each column by clicking on the column heading. Clicking on the same column heading again will sort the entries in reverse order. Drag and drop a column heading to change the position. Drag a column header separator to resize a column.
To view the log as a plain text file, hit the Text button. To always open it as text, check the corresponding item on the Options dialog.
For more details, download RW4M.