Many ISPs block outbound SMTP traffic to ensure that spammers do not abuse their service. You can validate whether you can send mail to remote hosts by using the telnet utility.
Instructions follow:
- From the Windows Start Menu select Start|Run and enter CMD as the application to run. Then click OK.
- At the command prompt, enter the following:
telnet mail.mailenable.com 25
The remote mail server should respond with an initiation string much like the following:
220 mailenable.com ESMTP Mail Enable SMTP Service, Version: xxxx ready at 02/28/03 14:04:45
- Type the word QUIT and then press enter.
If you were successfully able to do this, then no firewall (either local or your ISPs) is preventing outbound SMTP traffic.
The next procedure to try is sending an actual message to the remote host (rather than just determining whether you can connect to it).
This is outlined as follows:
- From the Windows Start Menu select Start|Run and enter CMD as the application to run. Then click OK.
- At the command prompt, enter the following:
telnet mail.mailenable.com 25
The remote mail server should respond with an initiation string much like the following:
220 mailenable.com ESMTP Mail Enable SMTP Service, Version: xxxx ready at 02/28/03 14:04:45
- Type the following: HELO YourDomainName and then press enter.
The server should reply with something like 250 xxxxxxxx
- Type the following: MAIL FROM: and then press enter.
The server should reply with something like 250 xxxxxxxx
- Type the following: RCPT TO: and then press enter.
The server should reply with something like 250 xxxxxxxx
- Type the following: DATA and then press enter.
The server should reply with something like 354 xxxxxxxx
- Enter the text as follows (Note: [CRLF] = Enter Key):
Subject: Test Message[CRLF] [CRLF].[CRLF]
- Type the following: QUIT and then press enter.
If you were able to do this then MailEnable should be able to send messages to the remote host. If your receive an abnormal response for any of the commands you typed in, then you should search the MailEnable knowledge base for any articles that may give an indication of the cause of the error.
Example:
C:\>telnet mail.mailenable.com 25
220 mailenable.com ESMTP MailEnable Service, Version: -1.110- ready at 11/20/03
23:49:40
EHLO test.mydomain.com.au
250-mailenable.com [144.136.51.56], this server offers 4 extensions
250-AUTH LOGIN CRAM-MD5
250-SIZE 10120000
250-HELP
250 AUTH=LOGIN
MAIL FROM:
250 Requested mail action okay, completed
RCPT TO:
250 Requested mail action okay, completed
DATA
354 Start mail input; end with [CRLF].[CRLF]
Subject: Test Message
.
250 Requested mail action okay, completed
QUIT
221 Service closing transmission channel
Connection to host lost.