SMTP Mail Debug

Test SMTP port 25 for reponse
telnet to mail server by name
i.e. telnet mail.geo.net 25

telnet to mail server by IP
i.e. telnet 192.231.42.3 25"

Verify domain via "whois geo.net" (or your domain)

Internic domain status is not "On Hold" usually due to lack of payment to Internic
Internic points to what primary and secondary name servers

Verify DNS

ping mail server by name, if above port 25 test failed
i.e. "ping mail.geo.net"

ping mail server by IP, if above ping by host name failed
i.e. "ping 192.231.42.3"

Verify "MX" records
nslookup
set q=mx
domain.com (or whatever domain name in question)

Verify "A" records
nslookup
set q=a
mail.domain.com (or whatever for host name of mail server in question)

Send test mail message

mailx -v chuck@geo.net
mail -v chuck@geo.net
sendmail -v chuck@geo.net

Bounce outgoing test mail off someone elses smtp server

i.e. "mail -v joe%domain.com@geo.net"
Substitute "geo.net" with whatever smtp mail server to use as a relay

SMTP Commands
Syntax Function
helo identify sending SMTP
mail from: chuck@skunk.net Senders Address
rcpt to:bill@theirdomain.com Recipients address
data begin a message
quit end SMTP session
expn expand alias
help request online help
rset abort a message
vrfy verify a user name


Suggestions... Send to: charly@skunk.net