| Software | Servidores | Porcentage |
|---|---|---|
| Postfix | 113 | 37.42 % |
| Sendmail | 69 | 22.85 % |
| QMail | 35 | 11.59 % |
| Google Mail SMTP | 24 | 7.95 % |
| Exim | 19 | 6.29 % |
| Microsoft ESMTP MAIL Service | 14 | 4.64 % |
| MDaemon | 7 | 2.32 % |
| eTrust Secure Content Manager | 6 | 1.99 % |
| PMDF | 5 | 1.66 % |
| eSafe | 3 | 0.99 % |
| ArGoSoft Mail Server | 2 | 0.66 % |
| Sun ONE Messaging Server | 1 | 0.33 % |
| Lotus Domino | 1 | 0.33 % |
| IMail | 1 | 0.33 % |
| InterMail | 1 | 0.33 % |
| MailSite | 1 | 0.33 % |