How to Manually Test if an SMTP server can Receive Email
Summary:
This document will help in troubleshooting server connectivity and steps to test if MailEnable can send to remote servers. Here are two ways you can manually test if an SMTP server can receive emails:
Using Telnet:
Note: Telnet might not be enabled by default on your system. Consider alternative methods if unavailable.
Steps:
Find the MX Record:
Open a command prompt.
Type nslookup <domain_name>.
Set type to MX: set type=mx
Press Enter
The first record is the primary mail server. Note the hostname.
Connect to the Server:
Type telnet <hostname> 25. Replace <hostname> with the server name from step 1.
Send Commands:
If connected, the server will respond with a welcome message.
Send the following commands, pressing Enter after each:
HELO yourdomain.com: Introduces you.
MAIL FROM: <your_email>: Sets sender address.
RCPT TO: <recipient_email>: Sets recipient address.
DATA: Starts message content.
Type your message body (lines starting with “.” end it).
. (on a new line) to send and quit.
Analyze Responses:
Each command should receive a response code (e.g., 250 for success, 550 for error). Successful connection and message sending will show codes like 220, 250, and 354.
2. Using Online Tools:
Several online tools offer simpler testing:
- MxToolbox: https://mxtoolbox.com/problem/smtp/
- GMass SMTP Tester: https://www.gmass.co/smtp
- Mailtrap: https://mailtrap.io/
- Sendgrid Test Email: https://docs.sendgrid.com/ui/sending-email/email-testing
These tools generally:
- Allow entering server details and email content.
- Send a test email and provide delivery reports.
- Offer additional features like spam score checks.
Choosing the method:
- Telnet offers more control and troubleshooting details.
- Online tools are simpler and user-friendly for basic testing.
Additional tips:
- Remember to replace placeholders like <domain_name>, <your_email>, and <recipient_email> with your actual information.
- Be aware that some SMTP servers might not allow connections from unknown users or may require authentication.
- If you encounter errors during the test, research the specific error code for troubleshooting.