>"Scott Q. via mailop":- <[email protected]> >I don't think so, the recipient domain is a gov entity: >muni-carta.go.cr > >Their MX records haven't changed in forever and most importantly, how >come we can e-mail them from another address ?
Has the SENDER domain recently migrated to/from M365? Examining the bounce message should reveal "Received:" headers showing the devices between which the email is looping. Also, it may be worth trying a different sending domain via the same outbound IP to see whether the issue is with the sending domain or IP. -- Best wishes, Matthew _______________________________________________ mailop mailing list [email protected] https://list.mailop.org/listinfo/mailop
