trouble with sending mail with Spring mail through somain registrar 1and1 smtp

Question

I\'m trying to send an email from a spring boot application with spring mail (1.5.8.RELEASE) JavaMailSender

sending through gmail SMTP is fine. however sending email th

Answer 1

the cause of the issue was - I didn't programmatically set the sender field (The "From" field) in my outgoing message

Once i set the From field the issue was resolved.

unfortunately the response from 1and1's SMTP was irrelevant ("550 invalid DNS MX or A/AAAA resource record")

Hope this helps anyone