everse DNS is not a valid Hostname by mxtoolbox.com on smtp see here
220 mail.pattola.com - Welcome to Qmail ESMTP
Test Result
SMTP Valid Hostname Reverse DNS is not a valid Hostname More Info
SMTP Reverse DNS Mismatch OK - 192.95.38.70 resolves to pattola.com
SMTP Banner Check OK - Reverse DNS matches SMTP Banner
SMTP TLS OK - Supports TLS.
SMTP Connection Time 0.783 seconds - Good on Connection time
SMTP Open Relay OK - Not an open relay.
SMTP Transaction Time 4.159 seconds - Good on Transaction Time
Session Transcript:
Connecting to 192.95.38.70
220 mail.pattola.com - Welcome to Qmail ESMTP [720 ms]
EHLO PWS3.mxtoolbox.com
250-mail.pattola.com - Welcome to Qmail
250-STARTTLS
250-PIPELINING
250-8BITMIME
250-SIZE 20971520
250 AUTH LOGIN PLAIN [688 ms]
MAIL FROM:<supertool@mxtoolbox.com>
250 ok [797 ms]
RCPT TO:<test@example.com>
553 5.7.1 sorry, that domain isn't in my list of allowed rcpthosts (chkuser) [1798 ms]
PWS3v2 5456ms