This was fixed in Debian with mutt version 1.5.20-8 which is available since Maverick Meerkat (10.10).
mutt | 1.5.20-9ubuntu2 | maverick | source, amd64, armel, i386, powerpc mutt | 1.5.20-9ubuntu2.1 | maverick-security | source, amd64, armel, i386, powerpc mutt | 1.5.20-9ubuntu2.1 | maverick-updates | source, amd64, armel, i386, powerpc mutt | 1.5.21-2ubuntu3 | natty | source, amd64, armel, i386, powerpc mutt | 1.5.21-2ubuntu3.1 | natty-security | source, amd64, armel, i386, powerpc mutt | 1.5.21-2ubuntu3.1 | natty-updates | source, amd64, armel, i386, powerpc mutt | 1.5.21-5 | oneiric | source, amd64, armel, i386, powerpc
This was fixed in Debian with mutt version 1.5.20-8 which is available since Maverick Meerkat (10.10).
mutt | 1.5.20-9ubuntu2 | maverick | source, amd64, armel, i386, powerpc
mutt | 1.5.20-9ubuntu2.1 | maverick-security | source, amd64, armel, i386, powerpc
mutt | 1.5.20-9ubuntu2.1 | maverick-updates | source, amd64, armel, i386, powerpc
mutt | 1.5.21-2ubuntu3 | natty | source, amd64, armel, i386, powerpc
mutt | 1.5.21-2ubuntu3.1 | natty-security | source, amd64, armel, i386, powerpc
mutt | 1.5.21-2ubuntu3.1 | natty-updates | source, amd64, armel, i386, powerpc
mutt | 1.5.21-5 | oneiric | source, amd64, armel, i386, powerpc