postfix error "connect from unknown"

[tomdf]

Hello guys,

i have many error messages from postfix :


connect from unknown [ip address]

i am running ubuntu 18.04

i think its spam.
can anyone give me an idea how to stop this spam?

i read already to change main.cf


smtpd_sender_reststricitons = reject_unknown_revers_client_hostname


but it does not work

maybe anyone can help me with this issue

thanks a lot

Tom

[SeijiSensei]

Is "revers" just a typo, or is it also spelled incorrectly in main.cf?

[tomdf]

hi, oh yes its just a typo my main.cf is this:



smtpd_helo_required = yes
smtpd_helo_restrictions = permit_sasl_authenticated, permit_mynetworks, check_helo_access regexp:/etc/postfix/helo_access, reject_invalid_hostname, reject_non_fqdn_hostname, reject_invalid_helo_hostname, reject_unknown_helo_hostname, check_helo_access regexp:/etc/postfix/blacklist_helo
smtpd_sender_restrictions = check_sender_access regexp:/etc/postfix/tag_as_originating.re , permit_mynetworks, permit_sasl_authenticated, reject_unknown_reverse_client_hostname, check_sender_access mysql:/etc/postfix/mysql-virtual_sender.cf, check_sender_access regexp:/etc/postfix/tag_as_foreign.re
smtpd_client_restrictions = check_client_access mysql:/etc/postfix/mysql-virtual_client.cf
smtpd_client_message_rate_limit = 100
maildrop_destination_concurrency_limit = 1
maildrop_destination_recipient_limit = 1
virtual_transport = dovecot


and the error message is this:



Mar 29 18:17:22 server1 postfix/smtpd[14983]: warning: unknown[91.212.150.158]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Mar 29 18:17:22 server1 postfix/smtpd[14983]: disconnect from unknown[91.212.150.158] ehlo=1 auth=0/1 rset=1 quit=1 commands=3/4
Mar 29 18:17:34 server1 postfix/smtpd[14996]: connect from unknown[93.157.63.30]
Mar 29 18:17:46 server1 postfix/smtpd[14996]: warning: unknown[93.157.63.30]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Mar 29 18:17:46 server1 postfix/smtpd[14996]: disconnect from unknown[93.157.63.30] ehlo=1 auth=0/1 rset=1 quit=1 commands=3/4
Mar 29 18:18:02 server1 postfix/smtpd[14983]: connect from unknown[91.212.150.158]
Mar 29 18:18:14 server1 postfix/smtpd[14983]: warning: unknown[91.212.150.158]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Mar 29 18:18:15 server1 postfix/smtpd[14983]: disconnect from unknown[91.212.150.158] ehlo=1 auth=0/1 rset=1 quit=1 commands=3/4
Mar 29 18:18:41 server1 postfix/smtpd[14996]: warning: hostname myort.net (http://myort.net/) does not resolve to address 93.157.63.6
Mar 29 18:18:41 server1 postfix/smtpd[14996]: connect from unknown[93.157.63.6]



i started postfix new

maybe you have any idea?
thanks so much for your help