I have a Ruby on Rails application than sends emails.
Recently my users started complaining than they didn’t recieved their emails. They vanished, they didn’t even reached spam folder.
I have set up SPF, DMARC and DKIM records on the configuration of my DNS, but I found out than the emails sent by my application don’t include a DKIM signature header. I thought it was injected by the SMTP server
How can I add the corresponding DKIM signature header if I have no access to mxroute’s DKIM private key?