Mail (MX) Server Survey
April 1st, 2025
| Report Description |
 |
This report is a comprehensive report involving all mail
servers we know of visible on the internet. For each domain in our
conventional web server survey, we also determine the list of mail servers
that provide inbound mail services (via MX record lookups). Each unique
mail server is connected to once each month, where we wait for the
server's "220 " message which usually accompanies a banner revealing
the server software being used.
| Basic Response Statistics |
|
When connecting to an MX server, a number of different responses are
possible. The remote server may not be up and running or completely
refusing connections, it may not respond back with a "220 " line
in the amount of time we wait, nor will it always provide a banner that
identifies the type of software running.
| Description> |
Number of Servers |
Percent |
| Total Number of MX Servers Queried | 1,054,705 | 100.0% |
| Number of Servers that didn't respond | 204,093 | 19.35% |
| Server didn't open socket | 201,696 | 19.12% |
| Server didn't provide banner | 2,397 | 0.23% |
| Server provided banner | 850,612 | 80.65% |
| Server banner identifies software in use | 538,383 | 51.05% |
As indicated by the above table, of the 1,054,705 servers
queried, only 538,383 servers
responded with a banner that allow us to identify the software being used.
All of the remaining information in this report is based on the responses
that allowed us to identify the software in use.
| Basic Technology Breakdown |
|
| Detailed Breakdown of Revisions on a Per-Server Basis |
|
| Exim (300,988 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 4.98.1 | 191,603 | 63.66% |
| 4.96.2 | 41,169 | 13.68% |
| 4.98 | 15,106 | 5.02% |
| 4.96 | 8,810 | 2.93% |
| 4.97.1 | 7,996 | 2.66% |
| 4.93 | 6,359 | 2.11% |
| 4.95 | 5,537 | 1.84% |
| 4.94.2 | 5,238 | 1.74% |
| Other | 19,170 | 6.37% |
| Postfix (203,211 servers) |
|
|
| Version |
Number of Servers |
Percent |
| Other | 203,211 | 100.00% |
| Sendmail (18,343 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 8.16.1 | 7,950 | 43.34% |
| 8.15.2 | 3,760 | 20.50% |
| 8.14.7 | 1,715 | 9.35% |
| 8.14.4 | 1,398 | 7.62% |
| 8.18.1 | 844 | 4.60% |
| 8.13.8 | 672 | 3.66% |
| 8.14.5 | 455 | 2.48% |
| 8.14.9 | 235 | 1.28% |
| 8.17.1 | 215 | 1.17% |
| 8.17.1.9 | 195 | 1.06% |
| Other | 904 | 4.93% |
| MailEnable (9,718 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 10.49-- | 3,237 | 33.31% |
| 10.46-- | 1,067 | 10.98% |
| 10.48-- | 567 | 5.83% |
| 10.34-- | 304 | 3.13% |
| 10.43-- | 206 | 2.12% |
| 10.50-- | 193 | 1.99% |
| 10.25-- | 192 | 1.98% |
| 10.47-- | 176 | 1.81% |
| 10.27-- | 173 | 1.78% |
| 10.43-10.43- | 145 | 1.49% |
| 10.48--10.48 | 116 | 1.19% |
| 9.00-- | 107 | 1.10% |
| 10.51-- | 106 | 1.09% |
| 10.47--10.47 | 103 | 1.06% |
| 10.42-- | 103 | 1.06% |
| 10.49-10.49- | 102 | 1.05% |
| Other | 2,821 | 29.03% |
| MDaemon (2,065 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 24.5.2 | 367 | 17.77% |
| 13.5.1 | 81 | 3.92% |
| 25.0.0 | 79 | 3.83% |
| 19.5.4 | 78 | 3.78% |
| 13.0.4 | 72 | 3.49% |
| 11.0.0 | 70 | 3.39% |
| 13.0.5 | 66 | 3.20% |
| 11.0.3 | 64 | 3.10% |
| 24.5.1 | 45 | 2.18% |
| 16.5.2 | 43 | 2.08% |
| 14.5.2 | 42 | 2.03% |
| 12.5.6 | 35 | 1.69% |
| 23.0.2 | 30 | 1.45% |
| 23.0.1 | 30 | 1.45% |
| 23.5.3 | 25 | 1.21% |
| 24.0.1 | 24 | 1.16% |
| 10.1.2 | 24 | 1.16% |
| 24.5.0 | 23 | 1.11% |
| 21.5.4 | 22 | 1.07% |
| 21.5.5 | 22 | 1.07% |
| 24.0.2 | 21 | 1.02% |
| Other | 802 | 38.84% |
| Microsoft (1,050 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 6.0.3790.4675 | 267 | 25.43% |
| 10.0.17763.1697 | 200 | 19.05% |
| 10.0.14393.4169 | 125 | 11.90% |
| 8.5.9600.16384 | 107 | 10.19% |
| 7.5.7601.17514 | 71 | 6.76% |
| 6.0.3790.3959 | 64 | 6.10% |
| 5.0.2195.5329 | 49 | 4.67% |
| 10.0.20348.1 | 38 | 3.62% |
| 8.0.9200.16384 | 21 | 2.00% |
| 5.0.2195.6713 | 20 | 1.90% |
| 6.0.3790.1830 | 12 | 1.14% |
| Other | 76 | 7.24% |
| CommuniGate Pro (651 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 6.2.15 | 56 | 8.60% |
| 6.3.39 | 41 | 6.30% |
| 6.2.14 | 41 | 6.30% |
| 6.3.17 | 25 | 3.84% |
| 6.1.20 | 23 | 3.53% |
| 6.4.1 | 23 | 3.53% |
| 6.3.20 | 21 | 3.23% |
| 6.4.0 | 21 | 3.23% |
| 6.3.18 | 19 | 2.92% |
| 6.0.11 | 12 | 1.84% |
| 5.2.20 | 11 | 1.69% |
| 6.1.16 | 11 | 1.69% |
| 6.2.12 | 10 | 1.54% |
| 5.1.16 | 10 | 1.54% |
| 6.3.19 | 9 | 1.38% |
| 6.3.14 | 9 | 1.38% |
| 5.4.11 | 9 | 1.38% |
| 6.0.9 | 9 | 1.38% |
| 7.1.10 | 9 | 1.38% |
| 6.3.6 | 7 | 1.08% |
| 7.1.8 | 7 | 1.08% |
| 6.1.18 | 7 | 1.08% |
| Other | 261 | 40.09% |
| OpenSMTPD (539 servers) |
|
|
| Version |
Number of Servers |
Percent |
| Other | 539 | 100.00% |
| XMail (406 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 1.27 | 271 | 66.75% |
| 1.22 | 90 | 22.17% |
| 1.26 | 16 | 3.94% |
| 1.25 | 9 | 2.22% |
| 1.24 | 8 | 1.97% |
| Other | 12 | 2.96% |
| IMail (293 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 12.6.1.4 | 51 | 17.41% |
| 9.23 | 24 | 8.19% |
| 12.5.6.101 | 22 | 7.51% |
| 12.5.8.41 | 21 | 7.17% |
| 12.5.8.59 | 19 | 6.48% |
| 12.5.3.93 | 14 | 4.78% |
| 12.5.7.59 | 13 | 4.44% |
| 8.22 | 12 | 4.10% |
| 8.05 | 12 | 4.10% |
| 12.5.6.105 | 11 | 3.75% |
| 12.5.8.58 | 10 | 3.41% |
| 12.5.4.146 | 6 | 2.05% |
| 12.5.5.115 | 6 | 2.05% |
| 12.4.1.15 | 6 | 2.05% |
| 12.5.5.117 | 6 | 2.05% |
| 7.07 | 5 | 1.71% |
| 12.3.0.100 | 5 | 1.71% |
| 11.5 | 5 | 1.71% |
| 8.00 | 4 | 1.37% |
| 12.5.8.54 | 3 | 1.02% |
| 8.21 | 3 | 1.02% |
| 6.04 | 3 | 1.02% |
| 12.6.0.20 | 3 | 1.02% |
| 10.02 | 3 | 1.02% |
| Other | 26 | 8.87% |
| SurgeSMTP (284 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 7.8k-1 | 50 | 17.61% |
| 7.8a-1 | 28 | 9.86% |
| 7.3o4-4 | 23 | 8.10% |
| 7.8g-1 | 21 | 7.39% |
| 7.7c-1 | 15 | 5.28% |
| 7.5c-1 | 13 | 4.58% |
| 7.8c2-2 | 12 | 4.23% |
| 7.3e2-2 | 11 | 3.87% |
| 7.6j-1 | 11 | 3.87% |
| 7.1e-1 | 8 | 2.82% |
| 6.9c-1 | 8 | 2.82% |
| 7.7i-1 | 7 | 2.46% |
| 7.5a-1 | 7 | 2.46% |
| 7.4o-1 | 6 | 2.11% |
| 7.2i-1 | 5 | 1.76% |
| 7.4e-1 | 5 | 1.76% |
| 6.5a2-2 | 4 | 1.41% |
| 7.8h-10 | 4 | 1.41% |
| 7.6h-2 | 3 | 1.06% |
| 7.8l-7 | 3 | 1.06% |
| Other | 40 | 14.08% |
| Qmail Toaster (177 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 1.03 | 116 | 65.54% |
| 1.3 | 55 | 31.07% |
| 1.03.5 | 4 | 2.26% |
| 1.03.6 | 2 | 1.13% |
| Other | 0 | 0.00% |
| MagicMail (155 servers) |
|
|
| Version |
Number of Servers |
Percent |
| Other | 155 | 100.00% |
| WinWebMail (147 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 4.5.0.1 | 28 | 19.05% |
| 4.2.0.1 | 19 | 12.93% |
| 4.4.0.1 | 18 | 12.24% |
| 3.8.1.3 | 15 | 10.20% |
| 3.9.0.7 | 13 | 8.84% |
| 4.3.0.1 | 6 | 4.08% |
| 3.8.0.1 | 5 | 3.40% |
| 4.0.0.1 | 4 | 2.72% |
| 4.1.0.1 | 4 | 2.72% |
| 3.9.0.1 | 4 | 2.72% |
| 3.7.7.3 | 3 | 2.04% |
| 3.7.1.1 | 3 | 2.04% |
| 3.9.2.1 | 3 | 2.04% |
| 3.7.3.1 | 3 | 2.04% |
| 3.9.3.1 | 2 | 1.36% |
| 3.7.6.1 | 2 | 1.36% |
| 3.9.5.3 | 2 | 1.36% |
| 3.8.6.1 | 2 | 1.36% |
| 3.8.1.1 | 2 | 1.36% |
| Other | 9 | 6.12% |
| Lotus Domino (101 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 8.5.3 | 18 | 17.82% |
| 8.5.3FP6 | 17 | 16.83% |
| 8.5.2 | 6 | 5.94% |
| 7.0 | 5 | 4.95% |
| 8.5.1 | 5 | 4.95% |
| 8.5.2FP1 | 4 | 3.96% |
| 6.5 | 4 | 3.96% |
| 6.5.1 | 3 | 2.97% |
| 8.5.3FP3 | 3 | 2.97% |
| 7.0.2 | 3 | 2.97% |
| 8.5 | 3 | 2.97% |
| 8.0 | 3 | 2.97% |
| 6.5.2 | 2 | 1.98% |
| 6.5.3 | 2 | 1.98% |
| 7.0.4FP2 | 2 | 1.98% |
| 7.5.1 | 2 | 1.98% |
| 7.0.3 | 2 | 1.98% |
| Other | 17 | 16.83% |
| Post.Office (57 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 4.4 | 26 | 45.61% |
| 4.2.2 | 10 | 17.54% |
| 3.5.3 | 5 | 8.77% |
| 4.1.2.4 | 4 | 7.02% |
| 4.3 | 4 | 7.02% |
| 3.5.1 | 3 | 5.26% |
| 4.2 | 1 | 1.75% |
| 3.9.2 | 1 | 1.75% |
| 3.1.2 | 1 | 1.75% |
| 4.2.1.1 | 1 | 1.75% |
| 4.2.1.3 | 1 | 1.75% |
| Other | 0 | 0.00% |
| Merak (50 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 8.9.1 | 16 | 32.00% |
| 8.0.3 | 12 | 24.00% |
| 7.6.1 | 8 | 16.00% |
| 7.4.5 | 2 | 4.00% |
| 8.3.8 | 2 | 4.00% |
| 6.0.8 | 2 | 4.00% |
| 8.0.1 | 1 | 2.00% |
| 8.9.2 | 1 | 2.00% |
| 6.1.0 | 1 | 2.00% |
| 8.5.0 | 1 | 2.00% |
| 7.5.2 | 1 | 2.00% |
| 7.6.0 | 1 | 2.00% |
| 7.4.4 | 1 | 2.00% |
| 5.8.2 | 1 | 2.00% |
| Other | 0 | 0.00% |
| Kerio (45 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 6.7.3 | 13 | 28.89% |
| 6.6.1 | 8 | 17.78% |
| 6.7.0 | 5 | 11.11% |
| 6.5.2 | 4 | 8.89% |
| 6.6.2 | 3 | 6.67% |
| 6.7.1 | 3 | 6.67% |
| 6.7.2 | 2 | 4.44% |
| 6.5.1 | 2 | 4.44% |
| 6.4.1 | 1 | 2.22% |
| 6.0.8 | 1 | 2.22% |
| 5.7.6 | 1 | 2.22% |
| 6.6.0 | 1 | 2.22% |
| 6.3.0 | 1 | 2.22% |
| Other | 0 | 0.00% |
| ArGoSoft (33 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 1.8 (1.8.9.6) | 10 | 30.30% |
| 1.8 (1.8.9.3) | 5 | 15.15% |
| 1.8 (1.8.9.5) | 4 | 12.12% |
| 1.8 (1.8.9.1) | 3 | 9.09% |
| 1.8 (1.8.7.3) | 2 | 6.06% |
| 1.8 (1.8.9.2) | 2 | 6.06% |
| 1.8 (1.8.8.8) | 1 | 3.03% |
| 1.8 (1.8.8.7) | 1 | 3.03% |
| 1.8 (1.8.3.5) | 1 | 3.03% |
| 1.8 (1.8.9.4) | 1 | 3.03% |
| 1.8 (1.8.5.9) | 1 | 3.03% |
| 1.8 (1.8.1.7) | 1 | 3.03% |
| 1.8 (1.8.8.9) | 1 | 3.03% |
| Other | 0 | 0.00% |
| GroupWise (31 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 24.4.0 | 7 | 22.58% |
| 18.3.1 | 4 | 12.90% |
| 18.2.1 | 3 | 9.68% |
| 18.1.1 | 2 | 6.45% |
| 18.5.0 | 2 | 6.45% |
| 18.2.0 | 2 | 6.45% |
| 24.2.0 | 2 | 6.45% |
| 14.2.1 | 1 | 3.23% |
| 24.1.0 | 1 | 3.23% |
| 14.2.3 | 1 | 3.23% |
| 7.0.3 | 1 | 3.23% |
| 18.4.1 | 1 | 3.23% |
| 24.3.0 | 1 | 3.23% |
| 18.3.0 | 1 | 3.23% |
| 18.0.2 | 1 | 3.23% |
| 14.0.0 | 1 | 3.23% |
| Other | 0 | 0.00% |
| Gordano Messaging Suite (GMS) (13 servers) |
|
|
| Version |
Number of Servers |
Percent |
| Other | 13 | 100.00% |
| OpenVMS (10 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 8.4 | 6 | 60.00% |
| 7.3 | 3 | 30.00% |
| 8.2 | 1 | 10.00% |
| Other | 0 | 0.00% |
| VisNetic (3 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 9.3.2.0 | 2 | 66.67% |
| 8.0.3 | 1 | 33.33% |
| Other | 0 | 0.00% |
| InterScan VirusWall (3 servers) |
|
|
| Version |
Number of Servers |
Percent |
| Other | 3 | 100.00% |
| Trend Micro (3 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 5.18 | 2 | 66.67% |
| 5.5 | 1 | 33.33% |
| Other | 0 | 0.00% |
| ModusMail (2 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 4.1.361.21 | 2 | 100.00% |
| Other | 0 | 0.00% |
| MessageWall (2 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 1.0.8 | 2 | 100.00% |
| Other | 0 | 0.00% |
| Mercury (1 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 4.x | 1 | 100.00% |
| Other | 0 | 0.00% |
| Mirapoint (1 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 4.4.5-GA | 1 | 100.00% |
| Other | 0 | 0.00% |
| Neon Mail Server (1 servers) |
|
|
| Version |
Number of Servers |
Percent |
| 3.1.2 | 1 | 100.00% |
| Other | 0 | 0.00% |
