Sasl auth for email is disconnect why?

Aug 18 22:45:27 localhost postfix/submission/smtpd[18335]: connect from unknown[45.125.65.37]
Aug 18 22:45:31 localhost postfix/submission/smtpd[18335]: warning: unknown[45.125.65.37]: SASL PLAIN authentication failed:
Aug 18 22:45:31 localhost postfix/submission/smtpd[18335]: disconnect from unknown[45.125.65.37] ehlo=2 starttls=1 auth=0/1 quit=1 commands=4/5
Aug 18 22:45:42 localhost postfix/submission/smtpd[18382]: warning: hostname liferson.de does not resolve to address 141.98.10.84: No address associated with hostname
Aug 18 22:45:42 localhost postfix/submission/smtpd[18382]: connect from unknown[141.98.10.84]
Aug 18 22:45:48 localhost postfix/submission/smtpd[18382]: warning: unknown[141.98.10.84]: SASL PLAIN authentication failed:
Aug 18 22:45:48 localhost postfix/submission/smtpd[18382]: disconnect from unknown[141.98.10.84] ehlo=2 starttls=1 auth=0/1 quit=1 commands=4/5
Aug 18 22:46:30 localhost postfix/submission/smtpd[18335]: connect from unknown[141.98.10.217]
Aug 18 22:46:35 localhost postfix/submission/smtpd[18335]: warning: unknown[141.98.10.217]: SASL PLAIN authentication failed:
Aug 18 22:46:35 localhost postfix/submission/smtpd[18335]: disconnect from unknown[141.98.10.217] ehlo=2 starttls=1 auth=0/1 quit=1 commands=4/5
Aug 18 22:47:06 localhost postfix/submission/smtpd[18382]: warning: hostname yell.woinsta.com does not resolve to address 141.98.11.19
Aug 18 22:47:06 localhost postfix/submission/smtpd[18382]: connect from unknown[141.98.11.19]
Aug 18 22:47:11 localhost postfix/submission/smtpd[18382]: warning: unknown[141.98.11.19]: SASL PLAIN authentication failed:
Aug 18 22:47:11 localhost postfix/submission/smtpd[18382]: disconnect from unknown[141.98.11.19] ehlo=2 starttls=1 auth=0/1 quit=1 commands=4/5
Aug 18 22:47:56 localhost dovecot: imap-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=167.94.145.58, lip=192.168.1.220, TLS: Connection closed, session=<Hz/DxYvm2LynXpE6>
Aug 18 22:48:15 localhost postfix/submission/smtpd[18382]: connect from unknown[141.98.10.81]
Aug 18 22:48:20 localhost postfix/submission/smtpd[18382]: warning: unknown[141.98.10.81]: SASL PLAIN authentication failed:
Aug 18 22:48:20 localhost postfix/submission/smtpd[18382]: disconnect from unknown[141.98.10.81] ehlo=2 starttls=1 auth=0/1 quit=1 commands=4/5
Aug 18 22:50:46 localhost postfix[18560]: Postfix is running with backwards-compatible default settings
Aug 18 22:50:46 localhost postfix[18560]: See http://www.postfix.org/COMPATIBILITY_README.html for details
Aug 18 22:50:46 localhost postfix[18560]: To disable backwards compatibility use “postconf compatibility_level=2” and “postfix reload”
Aug 18 22:50:46 localhost postfix/postfix-script[18574]: stopping the Postfix mail system
Aug 18 22:50:46 localhost postfix/master[6091]: terminating on signal 15
Aug 18 22:50:49 localhost postfix[18741]: Postfix is running with backwards-compatible default settings
Aug 18 22:50:49 localhost postfix[18741]: See http://www.postfix.org/COMPATIBILITY_README.html for details
Aug 18 22:50:49 localhost postfix[18741]: To disable backwards compatibility use “postconf compatibility_level=2” and “postfix reload”
Aug 18 22:50:49 localhost postfix/postfix-script[18804]: warning: symlink leaves directory: /etc/postfix/./cert.pem
Aug 18 22:50:49 localhost postfix/postfix-script[18807]: warning: symlink leaves directory: /etc/postfix/./makedefs.out
Aug 18 22:50:49 localhost postfix/postfix-script[18810]: warning: symlink leaves directory: /etc/postfix/./key.pem
Aug 18 22:50:49 localhost postfix/postfix-script[18978]: starting the Postfix mail system
Aug 18 22:50:49 localhost postfix/master[18980]: daemon started – version 3.4.13, configuration /etc/postfix
Aug 18 22:51:06 localhost dovecot: imap-login: Login: user=[email protected], method=PLAIN, rip=79.180.10.75, lip=192.168.1.220, mpid=19005, TLS, session=<+CMT0YvmXstPtApL>
Aug 18 22:51:06 localhost dovecot: imap([email protected])<19005><+CMT0YvmXstPtApL>: Connection closed (LIST finished 0.101 secs ago) in=56 out=1700 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Aug 18 22:51:07 localhost dovecot: imap-login: Login: user=[email protected], method=PLAIN, rip=79.180.10.75, lip=192.168.1.220, mpid=19007, TLS, session=
Aug 18 22:51:07 localhost dovecot: imap([email protected])<19007>: Connection closed (UID FETCH finished 0.038 secs ago) in=225 out=2610 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Aug 18 22:51:07 localhost dovecot: imap-login: Login: user=[email protected], method=PLAIN, rip=79.180.10.75, lip=192.168.1.220, mpid=19013, TLS, session=
Aug 18 22:51:08 localhost dovecot: imap([email protected])<19013>: Connection closed (UID FETCH finished 0.034 secs ago) in=190 out=1891 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Aug 18 22:51:49 localhost dovecot: imap-login: Login: user=[email protected], method=PLAIN, rip=185.62.122.4, lip=192.168.1.220, mpid=19046, TLS, session=
Aug 18 22:51:50 localhost dovecot: imap([email protected])<19046>: Connection closed (LIST finished 0.167 secs ago) in=56 out=1692 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Aug 18 22:51:51 localhost dovecot: imap-login: Login: user=[email protected], method=PLAIN, rip=185.62.122.4, lip=192.168.1.220, mpid=19048, TLS, session=
Aug 18 22:51:51 localhost dovecot: imap([email protected])<19048>: Connection closed (UID FETCH finished 0.105 secs ago) in=225 out=2602 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Aug 18 22:51:52 localhost dovecot: imap-login: Login: user=[email protected], method=PLAIN, rip=185.62.122.4, lip=192.168.1.220, mpid=19050, TLS, session=
Aug 18 22:51:53 localhost dovecot: imap([email protected])<19050>: Connection closed (UID FETCH finished 0.096 secs ago) in=190 out=1907 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0
Aug 18 22:52:46 localhost postfix/submission/smtpd[19153]: connect from unknown[141.98.10.194]
Aug 18 22:52:51 localhost postfix/submission/smtpd[19153]: warning: unknown[141.98.10.194]: SASL PLAIN authentication failed:
Aug 18 22:52:51 localhost postfix/submission/smtpd[19153]: disconnect from unknown[141.98.10.194] ehlo=2 starttls=1 auth=0/1 quit=1 commands=4/5
Aug 18 22:53:41 localhost postfix/submission/smtpd[19153]: warning: hostname srv-45-125-65-159.serveroffer.net does not resolve to address 45.125.65.159: Name or service not known
Aug 18 22:53:41 localhost postfix/submission/smtpd[19153]: connect from unknown[45.125.65.159]
Aug 18 22:53:47 localhost postfix/submission/smtpd[19153]: warning: unknown[45.125.65.159]: SASL PLAIN authentication failed:
Aug 18 22:53:47 localhost postfix/submission/smtpd[19153]: disconnect from unknown[45.125.65.159] ehlo=2 starttls=1 auth=0/1 quit=1 commands=4/5