Needing a solution to print double-side 5 x 7 post cards on 60 lbs cardstock

[deproctor]

I'm trying to find a printer that will print 60 lbs 5 x 7 cardstock in duplex (double-sided). I purchased and returned a MFP234sdwe printer which said in the product description it could handle. When I tried to print, the software for the printer said that I could not do both at the same time and asked me to either change the paper size to letter, or remove the 2-sided print setting.

I was told that I had to use the multi-purpose (aka - manual) tray except it would only accept one sheet at a time which does not work for me. 

Does anyone have a recommendation for a printer that has a large capacity multi-purpose tray that can print in duplex for my postcards?

Thanks

Don

[Valsimot]

The automatic duplex can only handle A4/letter size plain paper, you will not find an HP printer that will cover your needs.