I am trying to use the email to SMS gateway, but it is not working from one of my email servers, the tmomail.net mailservers reject the messages and state "Sender IP reverse lookup rejected" which usually implies reverse DNS is not properly set up. My reverse DNS /is/ properly set up, on both ipv4 and ipv6.
From another server that is almost identically configured including the same reverse DNS setup, it works.
I know my server is configured correctly, with SPF, DKIM, and proper reverse DNS.
Jul 29 02:21:43 ks28333 postfix/cleanup[16346]: 0DD486FA5C: message-id=<20180729012143.0DD486FA5C@mail.example.com>
Jul 29 02:21:43 ks28333 opendkim[2724]: 0DD486FA5C: DKIM-Signature field added (s=key1, d=example.com)
Jul 29 02:21:43 ks28333 postfix/qmgr[15754]: 0DD486FA5C: from=<user@example.com>, size=457, nrcpt=1 (queue active)
Jul 29 02:21:43 ks28333 postfix/smtp[16414]: < d79033b.ess.barracudanetworks.com[64.235.153.10]:25: 220 mail0.ess.barracuda.com ESMTP (mx37.ess.sfj)
Jul 29 02:21:43 ks28333 postfix/smtp[16414]: > d79033b.ess.barracudanetworks.com[64.235.153.10]:25: EHLO mail.example.com
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: < d79033b.ess.barracudanetworks.com[64.235.153.10]:25: 250-mx37.ess.sfj.cudaops.com Hello example.com [x.x.x.x], pleased to meet you
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: < d79033b.ess.barracudanetworks.com[64.235.153.10]:25: 250-PIPELINING
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: < d79033b.ess.barracudanetworks.com[64.235.153.10]:25: 250-AUTH LOGIN
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: < d79033b.ess.barracudanetworks.com[64.235.153.10]:25: 250-STARTTLS
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: < d79033b.ess.barracudanetworks.com[64.235.153.10]:25: 250 HELP
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: server features: 0x1015 size 0
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: Using ESMTP PIPELINING, TCP send buffer size is 4096
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: > d79033b.ess.barracudanetworks.com[64.235.153.10]:25: STARTTLS
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: < d79033b.ess.barracudanetworks.com[64.235.153.10]:25: 220 Ready to start TLS
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: certificate verification failed for d79033b.ess.barracudanetworks.com[64.235.153.10]:25: untrusted issuer /C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert High Assurance EV Root CA
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: > d79033b.ess.barracudanetworks.com[64.235.153.10]:25: EHLO mail.example.com
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: < d79033b.ess.barracudanetworks.com[64.235.153.10]:25: 250-mx37.ess.sfj.cudaops.com Hello example.com [x.x.x.x], pleased to meet you
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: < d79033b.ess.barracudanetworks.com[64.235.153.10]:25: 250-PIPELINING
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: < d79033b.ess.barracudanetworks.com[64.235.153.10]:25: 250-AUTH LOGIN
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: < d79033b.ess.barracudanetworks.com[64.235.153.10]:25: 250 HELP
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: server features: 0x1005 size 0
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: Using ESMTP PIPELINING, TCP send buffer size is 4096
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: > d79033b.ess.barracudanetworks.com[64.235.153.10]:25: MAIL FROM:<user@example.com>
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: > d79033b.ess.barracudanetworks.com[64.235.153.10]:25: RCPT TO:<1234567890@tmomail.net>
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: > d79033b.ess.barracudanetworks.com[64.235.153.10]:25: DATA
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: < d79033b.ess.barracudanetworks.com[64.235.153.10]:25: 250 Sender <user@example.com> OK
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: < d79033b.ess.barracudanetworks.com[64.235.153.10]:25: 250 Recipient <1234567890@tmomail.net> OK
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: < d79033b.ess.barracudanetworks.com[64.235.153.10]:25: 354 Start mail input; end with <CRLF>.<CRLF>
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: header_token: text / plain
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: header_token: 7bit
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: > d79033b.ess.barracudanetworks.com[64.235.153.10]:25: .
Jul 29 02:21:44 ks28333 postfix/smtp[16414]: > d79033b.ess.barracudanetworks.com[64.235.153.10]:25: QUIT
Jul 29 02:21:47 ks28333 postfix/smtp[16414]: < d79033b.ess.barracudanetworks.com[64.235.153.10]:25: 550 permanent failure for one or more recipients (1234567890@tmomail.net:550 Sender IP reverse lookup rejected) (in reply to end of DATA command))
Jul 29 02:21:47 ks28333 postfix/smtp[16414]: 0DD486FA5C: to=<1234567890@tmomail.net>, relay=d79033b.ess.barracudanetworks.com[64.235.153.10]:25, delay=4.3, delays=0.14/0.04/1.3/2.8, dsn=5.0.0, status=bounced (host d79033b.ess.barracudanetworks.com[64.235.153.10] said: 550 permanent failure for one or more recipients (1234567890@tmomail.net:550 Sender IP reverse lookup rejected) (in reply to end of DATA command))
I know my reverse DNS is set up correctly. Can someone with a clue tell me what I need to change?