אימיילים חוזרים מ-Amazon SES/SNS לא עובדים

Ok, I was able to find the log about the failed request, but I’m still lost about what could this be?

Encoding::UndefinedConversionError ("\xC3" from ASCII-8BIT to UTF-8)
app/jobs/base.rb:314:in `block in enqueue'
lib/mini_sql_multisite_connection.rb:68:in `after_commit'
app/jobs/base.rb:314:in `enqueue'
app/controllers/webhooks_controller.rb:117:in `aws'
lib/middleware/omniauth_bypass_middleware.rb:71:in `call'
lib/content_security_policy/middleware.rb:12:in `call'
lib/middleware/anonymous_cache.rb:355:in `call'
config/initializers/100-quiet_logger.rb:23:in `call'
config/initializers/100-silence_logger.rb:31:in `call'
lib/middleware/enforce_hostname.rb:23:in `call'
lib/middleware/request_tracker.rb:177:in `call'