Mailgun: "550 Requested action not taken error" when sending to specific domains

Question

I use mailgun to send mail and I get this error message:

550 Requested action not taken: mailbox unavailable invalid DNS MX or A/AAAA resource record

when I send mail to certain domains. An example of a problem domain is web.de

Sending to other domains via mailgun works very well, and in fact I can send mail to the problem domain simply from my gmail account.

In terms of DNS records, Mailgun indicates that my domain has been verified using TXT DNS records. My MX records point to another email provider that I use to receive email.

Answer 1

, - , , MX DNS Mailgun. , mg.yourdomain.com:

mxa.mailgun.org  10
mxb.mailgun.org  10

, MX ( mg.yourdomain.com). MX , .

. MX, (yourdomain.com), ( mailgun), . , / , . , ( ) MX .