[MM3-users] Re: Internal Server Error: /mailman3/accounts/fedora/login/

Look like a crawler-bot (e.g. for Search-Engines) is triggering this.

HTTP_USER_AGENT = 'Mozilla/5.0 (compatible; SemrushBot/7~bl; +http://www.semrush.com/bot.html)'

Not sure though, how they harvested the URL that is triggering the error. Maybe that URL is exposed somewhere, e.g. in Postorius or Hyperkitty.

Easy mitigation is to add a robots.txt with the following content to your site:

  User-agent: *
  Disallow: /

i.e. 'https://<your_site_url>/robots.txt' should return the above (or sth. alike).

I added an Alias pointing to a 'robots.txt' file to the apache2 config, e.g.:

      Alias /robots.txt           /var/www/robots/robots.txt