Telnet port 25 / Telnet SMTP commands / Check SMTP
Port
| 17-Jan-2025
You can check any SMTP Server on SMTP port 25 with the following Telnet commands. Open a command line and type:
This can also be achieved
If your server is online a connection will be established on
port 25 (SMTP). A Microsoft Exchange Server answers with the following
output:
214 HELO EHLO STARTTLS RCPT DATA RSET MAIL QUIT HELP AUTH TURN ATRN
ETRN BDAT VRFY
helo myserver.domain.com
# if nothing
happens, repeat this
250 mailserver.domain.com
Hello [10.1.11.105]
mail from:<myname@mydomain.com>
250 2.1.0 myname@mydomain.com....Sender OK
rcpt to:<recipientname@mydomain.com>
250 2.1.5 Recipient OK
data
354 Start mail input; end with <CRLF>.<CRLF>
subject: This is a test mail
to: recipientname@mydomain.com
This is the text of my test mail.
.
250 2.6.0 <exchange.domain.com> Queued mail
for delivery
quit
C:\Users\admin>portcheck -t smtp.office365.com 25 smtp.office365.com - Port 25 - OPEN - 30ms smtp.office365.com - Port 25 - OPEN - 34ms smtp.office365.com - Port 25 - OPEN - 40ms smtp.office365.com - Port 25 - OPEN - 47ms smtp.office365.com - Port 25 - OPEN - 30ms smtp.office365.com - Port 25 - closed smtp.office365.com - Port 25 - closed smtp.office365.com - Port 25 - closed smtp.office365.com - Port 25 - closed smtp.office365.com - Port 25 - OPEN - 30ms smtp.office365.com - Port 25 - OPEN - 29ms smtp.office365.com - Port 25 - OPEN - 41ms smtp.office365.com - Port 25 - OPEN - 33ms smtp.office365.com - Port 25 - OPEN - 38ms smtp.office365.com - Port 25 - OPEN - 32ms smtp.office365.com - Port 25 - OPEN - 34ms smtp.office365.com - Port 25 - OPEN - 30ms |
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