Hello! Our Support team would be happy to assist you with this via our website. This forum is monitored but not an active support channel- our site allows you to contact Support directly. We apologize for the delayed response to your issue and would like to provide support as soon as possible.
For assistance please contact SendGrid Support from the SendGrid Support Portal – https://support.sendgrid.com/. Click Login & Contact Support, and then Contact Support to see your support contact options. Paying SendGrid customers have the option to contact support via phone, chat, or by submitting a ticket using our web form. All SendGrid customers have the option to submit a ticket using our web form.
Our devs also mentioned that you could make a pull request in our WordPress Github to submit your plugin translation:
https://github.com/sendgrid/wordpress
This will allow our devs to look at your translation and let you know if it is something that could actually work with our plugin.
Thank you!