Thunderbird (31.6.0) seems to make random changes to the font in the first part of emails which I send. I always use TIMES, a font which has serifs, which I prefer. When I look at the sent email the first part has quite often been changed to a plain font without serifs. This altered font persists even when the email is printed to paper - the first part sans serif, the remainder in the original Times font. I have also checked by sending the emails to myself - the same font change occurs in the received email as well. The problem does not seem to occur in all emails, which tends to make it even more perplexing. The problem seems to occur in longer emails rather than in short ones. I have attached two sample screen shots for your interest - one the email using the original Times font and one showing as the email appears in the sent Folder or as received. There appears to be a bug in the software - it is making Thunderbird emails look scrappy and unprofessional both to the receiver and when printed and I believe deserves urgent attention. I do not recall this problem with earlier versions of Thunderbird. I am a VERY longterm user of Thunderbird having started using its predecessor when it was part of the Netscape browser. My current system: iMac (27-inch, Mid 2010) - 3.2 GHz Intel Core i3 - 16 GB 1333 MHz DDR3 - I am about to port everything over onto a brand new iMac 27-inch and I would really appreciate it if this problem could be sorted before I make the switch. Thanking you in anticipation. Yours faithfully, JOHNSWOOD CONTRACT FURNITURE PTY LTD RICHARD JOHNSWOOD Director JOHNSWOOD CONTRACT FURNITURE PTY LTD 12 HURMAN STREET ADELAIDE SA 5000