email server on a dynamic ip

ziggie216 · 12-22-2003, 03:46 AM

I found this page http://sbserv.stahl.bau.tu-bs.de/~hi...not_work.shtml

and they said about this

Quote:

Receiving mail
Why receiving mail does not work reliably:
If you register your dynamic IP in a dynamic DNS provider like dyndns.org, your dyndns.org hostname is assigned your dynamic IP
If your machine loses the internet connectivity, then the hostname will still point to your former IP
Now somebody else gets your former IP:
The computer has nothing listening on port 25:
No problem!
The computer has a properly setup MTA on port 25:
Your mail will be bounced! This is bad.
The computer has an open relay MTA on port 25:
Your mail will be relayed by this machine.
The computer has a blackhole MTA.
Your mail will be lost! This is bad.

true?

XavierP · 12-22-2003, 03:49 AM

Sounds about right to me. Your ip address is your pcs phone number - if your phone number is given to someone else then all your calls are lost.

It's the same thing with ip addresses. Always use a static ip address for servers which other pcs rely on.

rgerhards · 12-23-2003, 08:41 AM

Yes, the description is right - I know because I did this at home and have some friends who still do. It worked fine most of the time, but there is a certain risk involved. Make sure you do not intend to receive something important because some other party may read it.

Also, nowadays sending from a dynamic IP is a lot of troubles. First of all, many recipeints do no longer accept mail from dynamic IP blocks - too much spam. Secondly, more and more ISPs are blocking desitination port 25 - to many viruses... Hasn't the Internet become a nice place.

I now recommend - if you can afford it - to rent a relatively cheap email account that allows you to retrieve and deliver via their servers - much less hassle...