The best way to get help with Mail issues is to find what version of the Mac OS you have (it's not "iOS6" as that cannot run on a Mac computer) by doing "About this Mac" from your Apple menu. The real Mac OS version is the second line following the word "version.":
Once you have that, go to this forum area:
And post your mail question there. For some reason, Apple has always included software postings about Mail within the forum for the OS version with which it's bundled.
You'll get help much faster there that here, which tends to be more for hardware issues.