[swinog] Debugging bluewin.ch emails not going through

Hi,

I'm getting "421 EHLO temporary error - PTR lookup failed" when trying to send any email to @bluewin.ch recipients.

My mailserver is mail.swill.org with proper PTR records configured though:

$ dig +short -t ptr 203.200-30.135.144.213.in-addr.arpa @8.8.8.8 mail.swill.org.

$ telnet 195.186.120.50 25 Trying 195.186.120.50... Connected to 195.186.120.50. Escape character is '^]'. 220 mxbw.bluewin.ch vimdzmsp-mxin03.bluewin.ch Swisscom AG ESMTP server ready ehlo mail.swill.org 421 EHLO temporary error - PTR lookup failed

Is there someone from bluewin.ch here that can help me work through this?

best,

Maxim