Paper size A4

MailPrint is configured to print to my HP LaserJet 4 Plus on letter size paper, which is loaded in the printer. The printer is properly configured, as it prints from other apps. MailPrint generates a message on the printer to 'Load Paper Size A4'. I cannot find where this A4 size is coming from.

Thomas, Can you let me know what version of Windows you are using and I'll try and replicate the problem here. Tony