¿Qué es el puerto 25?

What is 25 port?

Port 25: SMTP port 25 continues to be used primarily for SMTP relaying. SMTP relaying is the transmission of email from email server to email server. In most cases, modern SMTP email clients (Microsoft Outlook, Mail, Thunderbird, etc.)

Port 25 is to be used for relaying messages between MTAs (Mail Transfer Agents) or from MSAs (Mail Submission Agents) to MTAs. This port also supports TLS encryption. SMTP was designated to use port 25 in IETF Request For Comments (RFC) 821. IANA still recognizes Port 25 as the standard, default SMTP port.

Port 587: The standard secure SMTP port Modern email servers use port 587 for the secure submission of email for delivery. For example, if you use an email client software like Outlook or Apple Mail, it most likely is configured to use this port to send your messages.

On your device or in your app, connect to smtp-relay.gmail.com on one of these ports: 25, 465, or 587.

Check port 25 in Windows

1. Open “Control Panel“.
2. Go to “Programs“.
3. Select “Turn Windows features on or off ”.
4. Check the “Telnet Client” box.
5. Click “OK“. A new box saying “Searching for required files“ will appear on your screen. When the process is completed, telnet should be fully functional.

The following steps are required on a Linux command line:

1. Execute telnet SERVERNAME 25 . This connects telnet to port 25 on the server with the name SERVERNAME.
2. If the TCP connection can be established, telnet responds with the message Connected to SERVERNAME.
3. Now you can send an e-mail via SMTP protocol.

Open MailEnable and expand Servers→localhost→Services and Connectors. Right click on SMTP service and click on Properties. Go to Inbound and click on Settings under Port Settings area. Select the checkbox for “Listen on alternate port” and type 587 in the field next to it.

Modern email servers use port 587 for the secure submission of email for delivery. For example, if you use an email client software like Outlook or Apple Mail, it most likely is configured to use this port to send your messages.

Ther is a picture. Swisscom is the internet provider for whole Swiss people. So, please I would be happy if I can get any answer for my question. As a result of the introduction of the new spam filter, e-mail that is sent with SMTP authentication via port 25 can no longer be sent.

Requests are reviewed and approved at Microsoft’s discretion and are only granted after anti-fraud checks are performed. To make a request, open a support case with the issue type Technical, Virtual Network Connectivity, cannot send e-mail (SMTP/Port 25).

Port 587: The standard secure SMTP port. Modern email servers use port 587 for the secure submission of email for delivery. For example, if you use an email client software like Outlook or Apple Mail, it most likely is configured to use this port to send your messages.