Overview of services running on Port 26 TCP.
~721 Thousand IP addresses observed from May to December 2012
To get raw lists of the data go to Download. For an explanation of what this data is and how it was obtained, see Paper.

Servicename	Product	Count	Percent
smtp	Exim smtpd	601199	83.363
smtp		27249	3.778
no match	-/-	21795	3.022
smtp	Postfix smtpd	10410	1.443
smtp	Microsoft ESMTP	9267	1.285
http		9263	1.284
smtp	Sendmail	7076	0.981
smtp	MailEnable smptd	5199	0.721
ssh	OpenSSH	3921	0.544
http	SonicWALL	3627	0.503
smtp	Microsoft Exchange smtpd	2463	0.342
chat	AIM or ICQ server	2187	0.303
http-proxy	Squid http proxy	1286	0.178
http	Apache	1029	0.143
arcserve	ARCserve Discovery	993	0.138
smtp	Symantec Enterprise Security manager smtpd	961	0.133
smtp	IMail NT-ESMTP	920	0.128
ssl	SSLv3	918	0.127
http	lighttpd	902	0.125
telnet	QDX 6000 Console Utility	714	0.099
ssh	Dropbear sshd	705	0.098
http	AIM	618	0.086
ftp	Microsoft ftpd	513	0.071
smtp	Alt-N MDaemon mail server	454	0.063
ssh	MikroTik RouterOS sshd	425	0.059
telnet		292	0.04
http	Microsoft IIS httpd	266	0.037
telnet	Intel telnetd	262	0.036
http	a_63	240	0.033
telnet	K80 Console Utility	231	0.032
smtp	Communigate Pro SMTP	219	0.03
smtp	Axigen smtpd	192	0.027
smtp	rblsmtpd wrapped smtpd	186	0.026
smtp	Kerio Connect smtpd	173	0.024
ftp	Serv-U ftpd	156	0.022
ssh		151	0.021
ftp		146	0.02
smtp	RaidenMAILD smtpd	144	0.02
smtp	MDaemon smtpd	135	0.019
telnet	Draytek Vigor ADSL router telnetd	133	0.018
smtp	Lotus Domino smtpd	126	0.017
smtp	IceWarp smtpd	120	0.017
ftp	ProFTPD	112	0.016
ftp	FileZilla ftpd	110	0.015
smtp	Microsoft Exchange 2010 smtpd	109	0.015
http	Microsoft HTTPAPI httpd	107	0.015
http	GoAhead-Webs httpd	105	0.015
http	Netwave IP camera http config	104	0.014
smtp	Barracuda Networks Spam Firewall smtpd	102	0.014
smtp	Rockliffe MailSite	98	0.014
smtp	MailEnable Enterprise smptd	92	0.013
telnet	Linux telnetd	88	0.012
smtp	Kerio MailServer	84	0.012
smtp	Surgemail smtpd	83	0.012
http	Apache Tomcat/Coyote JSP engine	81	0.011
http	Boa HTTPd	72	0.01
smtp	Allworx 6x VoIP phone smtpd	69	0.01
ssh	SCS sshd	68	0.009
ftp	vsftpd	68	0.009
http	Avtech AVN801 network camera	63	0.009
smtp	Merak Mail Server smtpd	61	0.008
http	thttpd	55	0.008
smtp	XMail SMTP server	54	0.007
http	Hikvision-Webs	52	0.007
vnc	VNC	49	0.007
pop3	hMailServer pop3d	49	0.007
smtp	ArGoSoft Mail Server Pro	47	0.007
smtp	Cisco PIX sanitized smtpd	42	0.006
http	PDR-M800	42	0.006
smtp	Code-Crafters Ability Mail Server smtpd	39	0.005
smtp	Novell GroupWise	38	0.005
http	CCProxy	36	0.005
smtp-proxy	ESET NOD32 anti-virus smtp proxy	34	0.005
napster	WinMX or Lopster Napster P2P client	32	0.004
ftp	Pure-FTPd	32	0.004
smtp	Tobit David.fx smtpd	30	0.004
http	mini_httpd	30	0.004
ftp	MikroTik router ftpd	30	0.004
ftp	Dreambox ftpd	29	0.004
smtp-proxy	UserGate smtp proxy	28	0.004
ssl	Microsoft IIS SSL	27	0.004
mysql	MySQL	25	0.003
http	nginx	25	0.003
ftp	Synology DiskStation NAS ftpd	24	0.003
http	GoAhead-Webs	23	0.003
ssh	Bitvise WinSSHD	22	0.003
smtp	Symantec Messaging Gateway smtpd	22	0.003
smtp	Cisco IronPort C160 firewall smtpd	22	0.003
telnet	Cisco 1721 router telnetd	20	0.003
ssh	SunSSH	20	0.003
http	Mbedthis-Appweb	20	0.003
telnet	Netopia ADSL router telnetd	17	0.002
ssh	WeOnlyDo sshd	16	0.002
http	Cross Web Server	16	0.002
smtp	PowerMTA smtpd	15	0.002
http	Gadspot/Avtech AV787 webcam http config	15	0.002
smtp	MailMarshal	14	0.002
ftp	DrayTek Vigor router ftpd	14	0.002
socks-proxy	CCProxy socks proxy	13	0.002
smtp-proxy	Scalix smtp relay	13	0.002
smtp	JAMES smtpd	13	0.002
http	uTorrent WebUI	13	0.002
http	uc-httpd	13	0.002
http	DVR Systems webcam http interface	13	0.002
ftp	Code-Crafters Ability ftpd	13	0.002
telnet	slush telnetd	12	0.002
ssh	Cisco SSH	12	0.002
mongodb	MongoDB	12	0.002
http-proxy	F5 BIG-IP load balancer http proxy	12	0.002
http	GeoVision GeoHttpServer for webcams	12	0.002
ftp	Gene6 ftpd	12	0.002
smtp	IA Mailserver smtpd	11	0.002
smtp	ArGoSoft Mail Server Freeware	11	0.002
http	Allegro RomPager	11	0.002
http	AIM HTTP	11	0.002
smtp	Webwasher CSM Suite smtpd	10	0.001
smtp	FirstClass SMTP server	10	0.001
openvpn	OpenVPN	10	0.001