Calling `add_bcc` after creating a mail intance fails.

[ManuelSaleta]

When I create a Mail.new and this instance includes the to property.

I will get the following error when trying to call, add_bcc

email client responded with: -- {:response=>#<SendGrid::Response:0x0000000121b09b50 @status_code="400", @body="{\"errors\":[{\"message\":\"The to array is required for all personalization objects, and must have at least one email object with a valid email address.\",\"field\":\"personalizations.1.to\",\"help\":\"http://sendgrid.com/docs/API_Reference/Web_API_v3/Mail/errors.html#message.personalizations.to\"}]}", @headers={"server"=>["nginx"], "date"=>["Fri, 26 Sep 2025 16:24:27 GMT"], "content-type"=>["application/json"], "content-length"=>["288"], "connection"=>["close"], "access-control-allow-origin"=>["https://sendgrid.api-docs.io"], "access-control-allow-methods"=>["POST"], "access-control-allow-headers"=>["Authorization, Content-Type, On-behalf-of, x-sg-elas-acl"], "access-control-max-age"=>["600"], "x-no-cors-reason"=>["https://sendgrid.com/docs/Classroom/Basics/API/cors.html"], "strict-transport-security"=>["max-age=31536000; includeSubDomains"], "content-security-policy"=>["frame-ancestors 'none'"], "cache-control"=>["no-cache"], "x-content-type-options"=>["no-sniff"], "referrer-policy"=>["strict-origin-when-cross-origin"]}>}

This happens when you try to call add_bcc to an mail instance, after having added a to parameter when building an email...

I found a work around by calling .add_to as part of personalization..
by including add_to as part of the personalization

              email.add_personalization(
                SendGrid::Personalization.new.tap do |p|
                  p.add_to(to_recipient)
                  p.add_bcc(bcc_recipient)
                end
              )