We had an account on SendGrid, and we used link branding with custom subdomain (emails.example.com). We stopped using SendGrid and switched to other email service, but we still want to support our old emails. Right now, old email links are working fine, as we still have DNS set to redirect from emails.example.com to sendgrid.net, and SendGrid still redirects to correct urls, but we are completely dependent on SendGrid right now, and we don't know if at some point in future SendGrid will simply stop redirecting this links.
So, the question is how we can redirect old email links to point to our website?
I think it's impossible, as link branding feature replaced not just domain, but also the path from the links.
Maybe someone from SendGrid will have some answer?