Cannot send mails from outside the network, but can receive mails

Posted on 2006-07-04
Medium Priority
Last Modified: 2011-10-03
Hi experts,

One of my proffessor is in italy for a trip. He called me up and says that he was not to able to send mails to other group, but he could receive the mails. He also gave me the ip address(192.168) to allow access to send mails . I have a little bit of idea that I need to add it in /etc/mail/access file , But I'm not sure if it is going to work. Can anyone tell me in detail how to allow him to send mails.

Question by:sundeepgopal
LVL 22

Expert Comment

ID: 17038742
You need to give a lot more information about how emails are sent. Sendmail? Qmail? Postfix? Client is Outlook, Outlook Express, Pine. Operating system involved - Linux I guess? What version and distribution? What errors are received? Are the mails sent, and not delivered? Log files are there any?

The only thing I can help you with from your Q is an excellent method of troubleshooting SMTP connections using Telnet:


If nothing else going through the process detailed here will help you understand how your mail system works.

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LVL 24

Accepted Solution

slyong earned 750 total points
ID: 17039599
Hi Sundeep,

His IP, 192.168.. is a private IP which is behind some NAT/Firewall.  To get the public IP which he is using, he can go to http://whatismyip.com/ to see what his IP is.  

The simplest solution  is not to reconfigure your (SMTP) server but to ask him to configure his mail client (Outlook, Outlook Express, Thunderbird, whatever) to use the SMTP of the ISP he connects to in Italy.

Expert Comment

ID: 17039637
Whatever smtp server he is using (the server used to send mail) filters IPs of servers attempting to send email based by IP. It's done to:
1. not to get blacklist by spamfilters, as they tend to blacklist people with open SMTP relays because spammers use these to avoid detection
2. to stop spammers (not too effective as some people including Bill Joy keep these open on principal) and spammers only need to have some many of these.
3. To not share resources with freeloaders :)

You can either reconfigure smtp used by your professor, or have him/her temporerily reconfigure outgoing mail server in their mail program. :)

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