You can verify the functional overview of SMTP from your Exchange server by using the following tools:
- nslookup
- telnet
- SMTPdiag
NSLookup is a great tool that comes with Windows that allows you to search DNS for information. This tool is installed along with the TCP/IP protocol through Control Panel.
To use nslookup – go start – run – type – cmd then ENTER. At command prompt
c:\nslookup
Default Server: esg-gs-01.magwinya.lan
Address: 10.11.1.12
> set q=mx
> magwinya.lan
Server: esg-gs-01.magwinya.lan
Address: 10.11.1.12
magwinya.lan
primary name server = esg-gs-04.magwinya.lan
responsible mail addr = hostmaster
serial = 153
refresh = 900 (15 mins)
retry = 600 (10 mins)
expire = 86400 (1 day)
default TTL = 3600 (1 hour)
> exit
With the above nslookup results you go straight to your next tool, which is Telnet.
C:\>telnet esg-gs-04.magwinya.lan 25
220 magwinya.co.za Microsoft ESMTP MAIL Service, Version: 6.0.3790.1830 ready at Mon, 10 Aug 2009 18:12:57 +0200
type ehlo magwinya.lan then enter.
250-magwinya.co.za Hello [10.11.1.10]
250-TURN
250-SIZE
250-ETRN
250-PIPELINING
250-DSN
250-ENHANCEDSTATUSCODES
250-8bitmime
250-BINARYMIME
250-CHUNKING
250-VRFY
250-X-EXPS GSSAPI NTLM LOGIN
250-X-EXPS=LOGIN
250-AUTH GSSAPI NTLM LOGIN
250-AUTH=LOGIN
250-X-LINK2STATE
250-XEXCH50
250 OK
type mail from:esglab@magwinya.lan then enter.
250 2.1.0 esglab@magwinya.lan….Sender OK
type rcpt to:123test@***.co.za then enter
type data
type Subject: 123 Test – Over! (From Telnet)
type Please reply if received
type a blank line
type a period (“.”) and press Enter – this marks the end of the message body. The receiving system will understand and return a prompt.
type quit
next to SMTPDiag