Maile Server - Sendmail

[Kostas Sfakiotakis]

Greetings Bret ,


Bret Stern wrote:
> I want to host my own mail server, and quit
> paying my ISP 24.95 per month for it.
> 
> My FC4 server has sendmail, (which I have
> shut off right now), but I would like to activate
> the service and start using my own server for mail.
> 
> What things do I need to do this?
> 
> What is an A record??

An

The "A" record is one type of  Resource Records used by DNS
It is the type of resource record used by   DNS in order to
translate the human readable URLs to computer understandable
IP Addresses . Although am not a master on DNS the form of an
A record would look something like

www.forthnet.gr		86400	IN	A	193.92.150.50

On the above line www.forthnet.gr is the human readable URL
( it's my ISPs URL )

The above record is valid for 86400 seconds or 24 hours after this
time period passes the Primary DNS Server responsible for the
above "A" record would have to check whether it is still valid or not .

Now since you are trying to set up a mail server there are two more 
types of
Resource Records you would have to setup .

The  "MX" or Mail eXchange record this record says to anybody that 
want's to
sent you an email the server they would have to contact in order to sent 
you an email .
For example .

forthnet.gr	86400	IN	MX	100 mailgate.forthnet.gr

Now the above line says that if you wish to sent me an email your ISPs 
mail server would have
to contact mailgate.forthnet.gr .
86400 plays again the same role .

Now one last thing that you have to consider since you are trying to 
setup an eMail eXchange
Server is the PTR or Pointer Record . What this record does is get an IP 
and return the
URL ( or the FQDN ) of the machine that the IP coresponds to  . For 
example :

24.150.92.193.in-addr.arpa. 86400 IN    PTR     mailgate.forthnet.gr

Now it is generally consider could practice  ( some mail servers may 
even refuse
to "work with" a mail server even he doesn't   a PTR record similar to 
the above
one AND an A record .



Kind Regards,
   Kostas