This is a very known and real problem. It seems that French colleagues were the champions of ``forgetting the dot'' with at least 532 suspect names. The absolute champion was the zone ``ircam.fr'' with 428 missing trailing dot errors in its master file, 214 were in MXs pointing to ``vaslav.ircam.fr.ircam.fr'' and the others 214 were also in MXs pointing to ``nadia.ircam.fr.ircam.fr''.
One of the most interesting repercussion of this error was the introduction of the zones ``adm.hj.se.adm.hj.se'', ``tekn.hj.se.tekn.hj.se'' and ``uki.hj.se.uki.hj.se''.