How to deal with the log, what does it mean?

Question

Domain Name System

Greetings colleagues, I encountered such a situation that this [email protected] constantly clogs the message queue and because of this there are not very pleasant consequences, up to 82 thousand messages are in the queue. What could it be? What does this mean?

5700333727D     753 Tue Aug  4 15:33:40  [email protected]
(delivery temporarily suspended: host mx-v01.bluewin.ch[195.186.120.50] refused to talk to me: 554 mxbw.lb.bluewin.ch vimdzmsp-mxin15.bluewin.ch Swisscom AG sc206: Blacklisting in effect - http://www.dnsbl.manitu.net/lookup.php?value=192.168.91.120)
                                         [email protected]

Data taken from "postqueue -p"

Answer 1

Your mailer is blacklisted. The link on which you need to go is indicated in the log. Unsubscribing from BL on the same site
82 thousand messages - a lot. Why has so much accumulated?

Answer 2

It seems that spam is being sent through your mail server, and as a result, your ip was blacklisted.
although it is strange that the server ip is 192.168.91.120

Answer 3

Why did you allow emails to be forwarded, anonymously, through your relay)

Answer 4

Well, you got a spammer :) This bluewin.ch says that you are on the black list, which he uses and will not accept mail from you.
Look for the mole.