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Community Member

827 router not connecting to smtp server

I have a 827 router going out to the inter net via a dsl line. I can get to the pop3 server but can not send mail to the smtp server. I was told that I should open port 25. I am not sure how to do that. This is the 1st time I am working with a router. Is there a way to look at the current settings on the router so is I mess things up I can set it back to the way it was.

Thanks for any help


Community Member

Re: 827 router not connecting to smtp server

I don't have any experience with the model 827 so I can't tell you for sure how to save a copy of the config file. Usually you have to set up a TFTP server on your network. One nice thing about MOST Cisco routers is that if you reboot the device without explicitly saving the config to NVRAM, it will boot with the old saved config. So you can experiment and still get back to where you started.

What I can tell you is that you generally open ports on firewalls - not routers. You would have had to have built an access list on the router for a port to be blocked. If you (or someone) did build a list, there is always the possibility of an "implicit deny" problem. When you build access lists in Cisco routers, you permit or deny packets and the list concludes with an implicit deny of anything that wasn't specifically permitted.

Community Member

Re: 827 router not connecting to smtp server

Hi John,

You must be running NAT on the 827. Use

ip nat inside source static tcp (SMTP SERVER ADDRESS)25 (VALID IP ADDRESS) 25.

This will statically map port 25 from your Valid address directly to your mail server. Don't forget to allow port 25 through your ACL's on the ATM port.

If you want, mail me with the following address and I'll provide you with a config complete with ACL's. Just fill in the blanks


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