This means that Exim has excellent integration facilities and can give system administrators what they ask for. Exim supports most of the MTA features in some way or another. Exim also goes with cPanel: one of the most common control panels for domain owners.
Sendmail loses to Postfix and Exim in all aspects including usability. In practice, there is no good reason for installing this MTA. At the same time, Sendmail is preinstalled on most commercial Unix operating systems. It is also a portable solution, which can be used on non-Unix systems, such as Windows. Are the reviewed MTAs good for that purpose?
On one hand, you can transform Postfix and Exim into a mail trap for internal testing. For this, you need to configure your MTA to listen to a different port for emails that are to be delivered to the single mailbox, then you have to specify a new router and define a corresponding transport. This is not very complex, but good in-house Linux skills are required. On the other hand, you can simply use Mailtrap, which already has all this implemented in its service.
For more on what else you can do with Mailtrap, read the Getting Started Guide. Exim can be used for site-specific processing or local mail delivery. Table of Contents. How to choose an MTA Postfix vs. Sendmail vs. Which MTA has better performance? Which MTA is more reliable and failsafe? Which MTA is easier to administer? Is there any reason to choose Sendmail? Sendmail generates new processes to handle sending and receiving emails.
These processes will exist until the end of the transmission, and then Sendmail can not exit, so your script program will not be able to restart Sendmail correctly. For Postfix, users only need to issue the command postfix reload, and Postfix will reload its configuration file.
In addition, for a mail server with tens of thousands of users, use a file to store, for example, the sender who matches the mail address sent by the user for example, the letter sent by bob is modified to sales example.
For a large number of users, the file will become very large, thereby affecting the operating efficiency of the system. Postfix can be integrated with a database backend currently only supports MySQL to store its configuration information. The database method is much more powerful than the file method in terms of scalability. Compliance with IBM's open source copyright license, users can freely distribute the software for secondary development.
The only limitation is that changes to Postfix must be returned to IBM. Because IBM funded the development of Wietse. Comparison with Qmail The disadvantage of Qmail is that the configuration method is inconsistent with Sendmail, and it is not easy to maintain.
And the meaning of Qmail's copyright license is very vague, and it was not even released with the software. From the application author: If you wish to distribute your modified version of Qmail, you must obtain my permission. Its first beta version 0. The current version is 1. Qmail's characteristic security In order to verify the security of Qmail, Qmail supporters even paid a reward of 00 to look for Qmail's security loopholes. One year later, the bonus was not received, but was donated to the Free Software Foundation.
At present, the authors of Qmail are also investing 0 to seek security holes in Qmail. Speed: Qmail can deliver about one million emails in a medium-sized system, and even handle more than , emails per day on a , supporting parallel delivery.
Qmail supports the parallel delivery of mail, and can deliver about 20 mails at the same time. The current bottleneck of mail delivery is the SMTP protocol.
Qmail's design goal is to eventually deliver approximately one million messages per day on a 16M machine. Reliability: In order to ensure reliability, Qmail only returns the result of successful processing when the mail is correctly written to the disk, so that even if a system crash or power failure occurs during disk writing, the mail can be guaranteed not to be lost.
It's redelivery. Very simple virtual domain management, there is even an add-on developed by a third party called vpopmail to support virtual POP domain. With this software package, POP3 users do not need to have a formal account with the system.
Use ezmlm to support user-controlled mailing lists. Mail users are isolated from system accounts, providing users with mail accounts does not require setting up system accounts for them, thereby increasing security. Of course, Sendmail has certain guarantees in terms of portability, stability, and ensuring that there are no bugs. But there are many posts on the Internet about attacking Sendmail, which is a nightmare for administrators. Sendmail has produced a group of experienced Sendmail administrators in the development process, and Sendmail has a large number of complete documentation, in addition to Sendmail's book: O'Reilly's sendmail book written by Bryan Costales with Eric Allman, there are a large number of tutorials on the Internet , FAQ and other resources.
These large amounts of documentation are very important for making good use of the various features of Sendmail. But Sendmai is currently a mature MTA. Of course, Sendmail has some shortcomings, and its characteristic features are too many, which leads to the complexity of the configuration file.
Of course, it is much easier to generate configuration files by using m4 macros. However, it is not easy to master all configuration options. Sendmail has had a lot of security holes in past versions, so the administrator has to upgrade the version quickly. And the popularity of Sendmail also makes it the target of attacks, which has advantages and disadvantages: this means that security holes can be discovered quickly, but it also makes Sendmail more stable and secure.
Another problem is that the general default configuration of Sendmail is to have the minimum security features, so that Sendmail is often vulnerable to attacks. If you use Sendmail, you should make sure that you understand the meaning and impact of each open option. Once you understand how Sendmail works, the installation and maintenance of Sendmail becomes very easy. Through Sendmail's configuration file, users can fulfill all their imaginable needs.
Qmail is an option, which specifically considers security issues in its design and implementation. If you need a quick solution such as a secure mail gateway, Qmail is a good choice. The configuration files of Qmail and Sendmail are completely different. For Qmail, it has its own configuration file, and the configuration directory contains different files, and each file realizes the configuration of different parts such as virtual domain or virtual host, etc.
These configuration instructions are well documented in man, but the code structure of Qmail is not very good. Qmail is much smaller than Sendmail, and it lacks some of the features of today's mail servers. Unlike Sendmail, qmail does not verify the domain name of the sender of the mail envelope to ensure the correctness of the domain name.
It does not provide support for RBL itself, but requires add-on to achieve. Similarly, Qmail can not refuse to accept the recipient does not exist letters, but first receive the mail, and then return to find the mail without this user. The biggest problem with Qmail is the handling of sending mail to multiple recipients. If you send a large email to multiple users in the same domain, Sendmail will only send a copy of the email to the destination mail server.
Qmail will connect multiple times in parallel, each time sending a copy to a user. If users want to send large emails to multiple users every day, using Qmail will waste a lot of bandwidth. Think of it this way: Sendmail optimization saves bandwidth resources and Qmail optimization saves time. If the user's system has a good bandwidth, Qmail will have better performance, and if the user's system has limited bandwidth resources and sends a lot of mailing list information, Sendmail is more efficient.
Qmail does not support. The following are some tasks that are not easy to complete with Qmail. To use Qmail to complete these tasks, you may need to implement it yourself or use an insufficiently reliable module provided by a third party. The source code of Qmail is easier to understand than Sendmail, which is an advantage for those who want to delve into the internal understanding of the MTA mechanism.
Qmail should also be more stable in terms of security. Although unsupported, and not currently in development Qmail hasn't been updated since , Qmail has a large fan base. Qmail is also faster, and scales better with higher mail loads than Sendmail. However, Qmail is not easy to configure, or easy to extend. Qmail does not support Sendmail milters, so any additional filters have to be specifically written for Qmail. Qmail is the default MTA in the popular Plesk control panel software.
Zimbra is the least popular of all the Linux mail server software mentioned. Zimbra is not designed for security, speed, or infinite customization- it is designed for group collaboration.
Zimbra is extremely easy to install and configure, but should not be used as a high performance MTA. Zimbra instead excels if you want to have a way to share calendars, files, and contacts with other users on the Zimbra mail server.
A web-based control panel allows an easy way to add or remove users from the mail server, and most configuration is just as easy. Zimbra offers a commercial version, as well as an open source version of it's mail server. Currently, no Linux distributions use Zimbra as the default mail server.
The best Linux mail server software for your needs can be either MTA mentioned in this article- it's all up to your needs. For most organizations and people, Sendmail fills that role very well. If you don't need enterprise features, or the best security record, Sendmail clearly stands out based on it's performance and features.
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