Aug 11 05:55:40 relay_host sendmail[25741]: [ID 801593 mail.notice] q7B4teTq025741: ruleset=check_rcpt, arg1=<[email protected]>, relay=you_host_name1.com [10.23.4.224] (may be forged), reject=550 5.7.1 [email protected]… Relaying denied. IP name possibly forged [10.23.4.224]

Aug 11 05:55:40 relay_host sendmail[25741]: [ID 801593 mail.info] q7B4teTq025741: from=[email protected]\_real\_host\_name.com, size=1741, class=0, nrcpts=0, proto=ESMTP, daemon=MTA-v4, relay=you_host_name1.com [10.23.4.224] (may be forged)

the Relay host won’t allow your email goes out. because your hostname is not match with DNS.

nslookup 10.23.4.224 , check the domain. and compare with your real host.