what is smtp relay

If the server is set to an unreachable extranet, can I use Phpmailer smtp to send mail? Long time is set to always prompt for message could not being sent. Mailer error:smtp Connect () failed. It suddenly occurred to me that my server was set to be inaccessible outside the network, can only be accessed by the extranet user form, this will cause the Phpmailer func

, Wincrash, and Blade Runner.Port: 22Services: SshDescription: Pcanywhere established TCP and this end port connection may be to find SSH. There are many weaknesses in this service, and if configured in a specific pattern, many of the versions using the RSAREF library will have a number of vulnerabilities.Port: 23Services: TelnetDescription: Telnet, an intruder searches for UNIX services remotely. In most cases, this port is scanned to find the operat

layer, transport layer, channel layer, presentation layer and application layer. The TCP/IP protocol uses a 4-tier hierarchy, and each layer calls its next layer of network to fulfill its needs. These 4 layers are: Application layer: A layer of communication between applications, such as simple e-mail transfer (SMTP), File Transfer Protocol (FTP), Network Remote Access Protocol (Telnet), and so on. Transport layer: In this layer, it provides data

What is IIS? IIS is a system-wide feature of the Windows operating system that provides services such as Web, FTP, NNTP, and SMTP, making it easy to post information on the network, including the Internet and local area networks. IIS is an abbreviation for Internet Informati

: telnet, HTTP, FTP, WWW, NFS, SMTP, etc. (2) Presentation Layer: The main function of this layer is to define the data format and encryption. For example, FTP allows you to transfer data in binary or ASII format. If binary is selected, the sender and receiver do not change the file content. If the ASII format is selec

When surfing the internet, we often see the word "Port" and often use the port number. For example, if "21" is added after the FTP address, "21" indicates the port number. So what does port mean? How can I view the port number? Does a port become the door to malicious cyberattacks ?, How should we face all kinds of ports? The following content will be introduced for your reference. Port Introduction: This a

Often have friends to consult the most fire software station small series, about the difference between switches and routers, in fact, if you have used the switch and router friends should be aware of, for everyone, switches and routers in the use of the biggest difference is that the router can achieve dial-up Internet, and then through sharing to many computers at the same time online, But the switch does not have the dialing function inside, but th

IIS (Internet Information Server) is a web service component, including Web servers, FTP servers, NNTP servers, and SMTP servers, it is used for Webpage Browsing, file transmission, news services, and email sending. It makes it easy to publish information on the Internet (including the Internet and Local Area Network. This article describes how to configure and m

What is Internet information Server (IIS)?Microsoft IIS is a Web server that allows information to be published on a public intranet or on the Internet. Internet Information Server transmits information by using Hypertext Transfer Protocol (HTTP). You can also configure the Internet Information Server to provide File Transfer Protocol (FTP) and gopher services. T

What is the difference between reset slave and reset master in MySQL? mysqlslave The reset slave syntax is as follows: RESET SLAVE [ALL] [channel_option]channel_option: FOR CHANNEL channel Among them, channel_option is mainly for multi-source replication introduced in 5.7.6. RESET SLAVE The official explanation

What is the difference between a vswitch and a vro? Can a vro be used as a vswitch ?, VroI often see some network friends asking about the difference between a vswitch and a vro. In fact, if you have used both a vswitch and a vro, you should know something about it. For everyone, the biggest difference between a vswitch and a vro is that a dial-up Internet access

Some friends often come to consult the hottest software station editor. If you know the difference between a vswitch and a vro, if you have used a vswitch and a vro at the same time, the biggest difference between a vswitch and a vro is that a dial-up Internet access can be achieved within the vro, and then the Internet can be accessed through sharing with multiple computers at the same time, but the vswitch does not have the dial-up function, however

Often see network friends in the difference between the switch and router, in fact, if you have used both switch and router friends should know, for everyone, switch and router use the biggest difference is that the router can realize dial-up internet access, and then shared to multiple computers at the same time the Internet, But the switch does not have the dial function, but the function of the switch is

In our previous studies on network protocols, we found that some references are explained by combining the BOOTP protocol, DHCP protocol, and DHCP server. So what is the relationship between DHCP and BOOTP? BOOTP relay proxy BOOTP (Bootstrap Protocol) relay proxy is an Inter

Ssl vpn Definition The development of ssl vpn is a supplement to the existing SSL applications. It increases the access control and security level and capability of the company. Ssl vpn also helps enterprises that use remote access to the application system to reduce their security. In terms of attributes, dialing ensures relative security, because a specific telephone line can identify a user. The client/server and the earlier version of VPN also hav

Summary I wanted to write a tutorial on port for a long time, and I finally put it into practice today. In fact, there are many tutorials on port introduction on the Internet, but I haven't seen any articles that really tell you what port is (maybe I didn't really see it). If you have read a lot of port tutorials, what is