Funny headers and other non-standard stuff found in SMTP headers and whatnot.

https://www.shodan.io/host/37.120.179.86#25

220 mail.geekify.de Security is like an onion - the more you dig in the more you want to cry.
250-mail.geekify.de

https://www.shodan.io/host/98.110.210.76#25

220 pi.hypertouch.com ESMTP CommuniGate Pro 6.2.14. It is you again :-(
250-pi.hypertouch.com host name is unknown s9yhh2qb9k7gpp.com

https://www.shodan.io/host/194.132.234.5#25

220 fogelholk.se - Bring it! I'd love those muffins you have there!
250-fogelholk.se

https://www.shodan.io/host/45.32.128.194#25

220 thunderbowl.wente.com ESMTP laser tinted braindeath Postfix ready for love
250-thunderbowl.wente.com

https://www.shodan.io/host/96.27.204.52#25

220 mailmon.answerexcellence.com ESMTP Hi, I'm a friendly email server just looking for a love to call my own.
250-mailmon.answerexcellence.com

https://www.shodan.io/host/37.59.203.147#25

220 SMTP02.getehlo.be She says EHLO you fool I love you
250-SMTP02.getehlo.be

https://www.shodan.io/host/178.238.149.202#25

220 love.warhead.org.uk ESMTP Love is in the air...
250-love.warhead.org.uk

https://www.shodan.io/host/194.135.211.9#25

220 mx1.agat-roscosmos.ru I love this game :-)
250-mx1.agat-roscosmos.ru

https://www.shodan.io/host/94.127.66.221#25

220 mailserver at sendmail.netwh.ru greets you. Make love not war!
250-sendmail.netwh.ru

https://www.shodan.io/host/46.28.110.74#25

220 smtp.mgrivna.cz here
554 fuck shodan making money out of vulnerabilities

https://www.shodan.io/host/18.18.160.24#25

220 FUCK-THE-SKULL-OF-JESUS.MIT.EDU running Eudora Internet Mail Server 3.2.5 demo
250-FUCK-THE-SKULL-OF-JESUS.MIT.EDU hello 12h384ngjk65.com (224.124.14.242)

https://www.shodan.io/host/94.16.105.207#25

220 mail.c0r.de ESMTP Fuck off
250-mail.c0r.de

https://www.shodan.io/host/163.172.139.228#25

550 no FCrDNS so fuck off

https://www.shodan.io/host/128.199.44.47#25

220 zicar.info ESMTP Postfix (Ubuntu) - fuck you ISPs blocking smtp
250-zicar.info

https://www.shodan.io/host/23.137.249.23#25

220 mail.chaox.ro ESMTP Chaox Operations eMail. You fuck up with our mail server we'll send your IP to the Iranian govt for haram!
250-mail.chaox.ro

https://www.shodan.io/host/15.204.210.128#25

220 mx.dragynfruit.com Stalwart ESMTP at your service
250-mx.dragynfruit.com you had me at EHLO
250-STARTTLS
250-SMTPUTF8
250-SIZE 104857600
250-REQUIRETLS
250-PIPELINING
250-NO-SOLICITING GO FUCK YOURSELF

https://www.shodan.io/host/111.231.165.167#25

220 mtash.yunrelay.cn ESMTP
554 Rejected - Go fuck away you scan or attack network!

https://www.shodan.io/host/77.55.215.149#25

220 server760974.nazwa.pl ESMTP Postfix (if you're not from 0xredbeef.tech GET THE FUCK OUT!!!)
250-server760974.nazwa.pl

https://www.shodan.io/host/51.38.70.205#25

220 FUCK YOU STOP SPAMMING MY ESMTP SERVER
250-mana.ping.fr

https://www.shodan.io/host/46.175.16.239#25

220-charts.gov.ua ESMTP Mon, 10 Nov 2025 02:34:13 +0200
220-all transactions and ip addresses are recorded.
220-When you try to hack and spam,
220 the entire subnet of the provider is blocked.
250-charts.gov.ua Hello g0te4y8b2ayo.org [224.156.42.205], pleased to meet you

https://www.shodan.io/host/194.186.195.171#25

220-MUP STE SMTP server is pleased to see you.
220-Please, behave yourself!
220-You are not allowed to spam!
220-You are not allowed to crack or hack the server!
220-
220 I'm sure we'll enjoy making good work together.
250-smtp.sochi-teplo.ru Hello 224.60.6.184 [224.60.6.184]

https://www.shodan.io/host/50.251.160.28#25

220-mx.n0spam.net ESMTP Wed, 19 Nov 2025 15:36:03 -0500
220-Account login hack attempts are immediately banned. 
220 Scanners and spammers are also blocked. 
250-mx.n0spam.net Hello 224.60.6.184 [224.60.6.184], pleased to meet you

https://www.shodan.io/host/91.249.211.166#25

220 Hack - Spam me and you will die !
250-mx01.plainet.de

https://www.shodan.io/host/81.90.243.184#25

220 mail.jakubschmidt.cz No Hack To My Castle
250-mail.jakubschmidt.cz

https://www.shodan.io/host/207.188.167.125#25

220-sima.cat ESMTP server ready.
220-Welcome to SIMA sl mail server
220 Do not spam, hack or try to rely and we won't blacklist you
250-sima.cat Hello 1veu1mp4fdmx.com; ESMTPs are:

https://www.shodan.io/host/103.18.55.83#25

220-mail.kcit.me ESMTP MDaemon 21.0.1; Thu, 27 Nov 2025 02:31:21 +1000
220-**********************************************************************
220-Unauthorised relay prohibited.
220-**********************************************************************
220-All transactions and IP addresses are logged for security reasons.
220-**********************************************************************
220-If your email server has been blacklisted please contact
220-your mail provider or IT department for assistance.
220 **********************************************************************
250-mail.kcit.me Hello lodnovxsrv010.org [224.226.160.33], pleased to meet you