je reçois systématiquement le message d'erreur 550-5.7.30 sur des messages que j'envoie aux adresses terminées par ...@gmail.com

   550-5.7.30 Your email has been blocked because DKIM authentication didn't
   pass 550-5.7.30 for this message. Gmail requires all email bulk senders to
   550-5.7.30 authenticate their email with DKIM. 550-5.7.30  550-5.7.30
   Authentication results: 550-5.7.30  DKIM = did not pass 550-5.7.30  To set
   up DKIM for your sending domains, visit 550-5.7.30
   https://support.google.com/a?p=turn-on-dkim  550-5.7.30 To learn more about
   Gmail requirements for bulk senders, visit 550 5.7.30
   https://support.google.com/a?p=sender-guidelines.
   ffacd0b85a97d-487245a57a8si2910364f8f.321 - gsmtp (in reply to end of DATA
   command)

First, i use Thunderbird 153.3.1 esr (64 bits). My browser is Firefox 156.0 (64 bits) and my Internet service provider is Free (from France). My issue is I receive an error message (505-5.7.30) when I send a mail to one ou some people. At every time, the error comes from adree finished in ...@gmail.com This is the end of the error message i receive : 'The mail system <(hidden identify).54@gmail.com>: host gmail-smtp-in.l.google.com[173.194.76.27] said: 550-5.7.30 Your email has been blocked because DKIM authentication didn't pass 550-5.7.30 for this message. Gmail requires all email bulk senders to 550-5.7.30 authenticate their email with DKIM. 550-5.7.30 550-5.7.30 Authentication results: 550-5.7.30 DKIM = did not pass 550-5.7.30 To set up DKIM for your sending domains, visit 550-5.7.30 https://support.google.com/a?p=turn-on-dkim 550-5.7.30 To learn more about Gmail requirements for bulk senders, visit 550 5.7.30 https://support.google.com/a?p=sender-guidelines. ffacd0b85a97d-487245a57a8si2910364f8f.321 - gsmtp (in reply to end of DATA command) " I have need a translator to read and understand all of that... But when I go on Google support to have the way to solve my problem, the explanations are too complicated for me ! Lionel Grosselin