I do get e-mails with MIME encoded (Encoded-Word) sender or recipient display name. The source is something like: From: =?iso-8859-1?Q?M=FCller,?= Thomas <thomas.mueller@example.com> Claws Mail displays the complete text, though "Müller, " is just plain text and "Thomas <thomas..." is a mailto link. Clicking on the Link you get a new message window with just "Thomas <thomas...". Replying to the mail the recipient is: To: "=?iso-8859-1?Q?M=FCller,\?=" Thomas <thomas.mueller@example.com> Which is shown as (note the quotation marks and backslash): To: "Müller,\" Thomas <thomas.mueller@example.com>
It should be quoted, e.g. From: "=?iso-8859-1?Q?M=FCller,?= Thomas" <thomas.mueller@example.com>