Sendmail on a LAN

Gordon Messmer yinyang at
Tue Aug 17 23:35:12 UTC 2010

On 08/17/2010 02:28 PM, JD wrote:
> So, why would any mail client/server send an email message
> to my ip address on a port other than 25?

They never would.

> Seems that I would need to configure the dydns account to
> forward the email to me on that alternate port, no?

Yes.  I merely meant that if you configured the firewall to direct port 
8025 to your sendmail server's port 25, you wouldn't have to take the 
step of reconfiguring sendmail.  You'd only need to set up an external 
MX at DynDNS, configure your dns MX record to point to their servers, 
and configure your router to forward the appropriate port.  No small 
configuration, but one that doesn't modify sendmail.

On the other hand, if your ATT firewall's configuration is simply to 
forward all ports, then you *would* have to modify sendmail.  I normally 
don't do that.  I forward only specific ports, and most firewall will 
allow you to set the destination port to something other than the original.

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