Your webmail system most likely has a Settings or Options where this can be set, or you may be able to click on the header(s) '''above''' the columns in your webmail - clicking on the 'date' or 'received date' or whatever it might be called column header, may select the sorting method in your webmail. You don't mention which webmail system you're using, so it is hard to make more accurate suggestions - but it is not very likely that this is really a Firefox problem; most likely any other browser would receive the same default setting when visiting this webmail system. I find it somewhat strange that your webhost blames Firefox, instead of telling you how to change this setting in the webmail system - I'm a webhost myself, and certainly knows that the server setup determines how mails are being sorted for display in any browser using a webmail system. The browser simply shows data in the order it is sent to it, to the very best of my knowledge - and this goes for any browser and any webmail system I've ever heard of. If you can give more details about the webmail system in question, we may be able to help you find information to change the display order of your mails, however. Please let us know how above works out, and if we can be of further assistance. Detailed feedback is appreciated and helps us to help you better, plus enables us to better help other users with similar issues.