Hi,
the ARC seal of your message looks fine, but does not seem to be wrapped to 78 characters per line:
ARC-Seal: i=1; a=rsa-sha256; d=mta.somaf.de; s=arcseal202101; t=1621356898; cv=none; b=T8A5bAtaHHEFFACKjbKDGWXujMFGUASy/2fo0A8xt+Eb8TFrdEuxay1dLceyeJDnN18NjLlziiryeCpzytAdJhpicI/qF33TNo5BS/tOSClnWHmLgT9VSV+Rks2LxS8LPnLcdOn3EpSQ5njy08hmVgO1IPG2ls6BihJMixtD0YVJCpcqol6sPp7TCtA9DkWbGNA15HidQ0M/RlG+pO0iXSq0zWW6BYxSBv1sxT4DtGkcXKGC6SucSU6u4yuI5///lxjzE4P1du74PGimRS7OTKoF2iDRkgZDIgoEzphm0K/59gN6u/lj1+49Dng/s10nDtfZc4RlKj7MBy0yWkU0WQ== ARC-Message-Signature: i=1; a=rsa-sha256; d=mta.somaf.de; s=arcseal202101; t=1621356898; c=relaxed/relaxed; bh=9x3e0pbvnFZ44Xlqiy+sUTqdsNeLpA7bN+NVpAL9Y6k=; h=To:DKIM-Signature:From:Subject:Message-ID:Date:MIME-Version: Content-Type:Content-Language:Content-Transfer-Encoding; b=tT1MXPeR3M0r6lOf2Z2/YNl5rytlsmlXNYjMIVxKMdIUP0+wSE6vehpq5fp2BHMzYmvoe7kGRNCCmI417xK4OjbnLlH7t7YV54V2i6p+pJUpCczRhz9D2jh7aa5ZNckndB8gC4dNE1ijbwaXBB8XeXD5TVd+Zi6dmJVD68cXE5X/auDwjpTgREwAWHvWPYMfMyIrQcQhO+c4Re8cQVpLVw9G+s+E2ZumGHkT+kUa9BddGBa3fyq2lm/1GlO5XHvJvHCm+m6Ub82x+7j+V1VaTwFh1lWcYOJ8k2djc018v3Y61HW5TUMxhXOaCObRyL3rvW+gUWGMw/CinguLtZqZsw== ARC-Authentication-Results: i=1; mta.somaf.de
Just a small issue - perhaps some ARC validators might stumble across this...
Thanks, and best regards, Peter Müller