Thanks, but printing in the latest Firefox/Thunderbird won't solve this situation entirely.
The use case is in printing envelopes from Lotus SmartSuite where the IBM Laserjet4 PCL driver does work, but the PostScript driver with my best-guess PPD does not work.
Firefox/Thunderbird will crash if they use this driver. I made another thread some time ago for that crash, which is a known problem with IBM graphics, and Firefox development will eventually work around it. I guess what would really fix this is if Firefox/Thunderbird did not crash while using the laserjet4 PCL driver.
If separate printer objects are provided, one per driver, then I suppose everything prints, but then in Thunderbird, the alternate printer driver has to be selected or it will crash. If Thunderbird could be set to print from the alternate printer, while all other programs continue to use the default printer, then that would be a slick solution.
Is there any way to force Thunderbird to default to an alternate (non-default) printer?