I use Laravel and Mailgun to send client notifications. Some emails send correctly to providers like Gmail and Hotmail, yet messages to certain domains fail due to a missing sender domain error.
hey try checkin your domain verification in mailgun and also update your dns spf/dkim records. i had a similar issue cause by a small misconfiguraiton, so revisiting your settings might help.
Considering similar issues I faced recently, I found that it was essential to double-check the domain verification process on Mailgun. I went back and re-assessed the setup, making sure that every detail in the DNS, particularly the SPF and DKIM records, aligned directly with Mailgun’s requirements. In my situation, regenerating the configuration and ensuring there were no conflicts with another service resolved the issue. Even minor discrepancies in the records can cause these errors, so a thorough review is advisable.