MailEnable Standard Guide
Manually testing if MailEnable can send mail to remote servers
Operational Procedures > Manually testing if MailEnable can send mail to remote servers
Many ISP’s block outbound SMTP traffic to ensure that spammers do not abuse their service. It is possible to validate whether mail can be sent to remote hosts by using the telnet utility.

Instructions follow:

  1. From the Windows Start Menu select Start|Run and enter CMD as the application to run. Select 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 MailEnable Service, Version: --10.0 ready at 11/09/17 14:04:45

Type the word QUIT and then press enter.

If this was successful, then no firewall (either local or the 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 it is possible to connect). Firstly, determine which remote server to connect to. A domain may have more than one server that is accepting email, and these servers may not match the domain name. The MX records that have been configured in a DNS determine the mail servers for a domain. To retrieve the mail server details for a domain, use the nslookup command line utility. For example, to check which servers are accepting email for AOL, you can enter:

nslookup –type=MX aol.com

This will return the details of the mail servers, these results can be used as the hosts to connect to.

This is outlined as follows:

  1. From the Windows Start Menu select Start|Run and enter CMD as the application to run. Select OK.

  2. 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 MailEnable Service, Version: --10.0 ready at 11/09/16 14:04:45

  3. Type the following and press Enter: HELO YourDomainName

    The server should reply with a line similar to:

    250 Requested mail action okay, completed

  4. Type the following and press Enter. Senderaddress is the email address you are sending from:

  5. MAIL FROM:<senderaddress>

    The server should reply with a line similar to:

    250 Requested mail action okay, completed

  6. Type the following and press Enter. Recipientaddress is the email address you are sending to:

    RCPT TO:<recipientaddress>

    The server should reply with a line similar to:

    250 Requested mail action okay, completed

    To have multiple recipients for an email, enter the recipient to line more than once. This is how a blind carbon copy works. If the recipient does not exist, this may generate an error such as:

    550 Requested action not taken: mailbox unavailable or not local

  7. Now indicate to the server that you want to send the email date. Type the following and press Enter: DATA

    The server should reply with something like

    354 Start mail input; end with <CRLF>.<CRLF>

  8. Enter the text of an email as follows (Note: [CRLF] = Enter Key). The period character on the last line indicates that all the email content has been sent:

    Subject: Test Message[CRLF]

    [CRLF].[CRLF]

  9. Type the following and press Enter:

    QUIT

If this was successful, then MailEnable should be able to send messages to the remote host. If an abnormal response is received for any of the commands typed in, then 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: --10.0 ready at 11/09/17 23:49:40

EHLO test.mydomain.com.au

250-mailenable.com [192.168.1.1], this server offers 4 extensions

250-AUTH LOGIN CRAM-MD5

250-SIZE 10120000

250-HELP

250 AUTH=LOGIN

MAIL FROM:<senderaddress>

250 Requested mail action okay, completed

RCPT TO:<recipientaddress>

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.