LUG: Sendmail and Squirrelmail - Mon, 28 Nov 2005 09:00:07 -0600

I am somewhat new to linux so please forgive if this is a stupid or newbie question. I am setting up a fedora core 4 linux server to run sendmail and squirrel mail for webmail. I also have dovecot installed but I'm not 100% sure that I need it.

If my understanding of the mail server is correct, I need to be running sendmail (its the MTA), dovecot (for IMAP/POP3 protocol), and squirrelmail (webmail) to have this mail server setup properly, is this correct? I want my users to use imap to get their mail for security reasons. We only have about 20 users or so will be using this but they do a lot of email. Am I correct in feeling that I need all three of these programs to get the mail system and webmail running?

If I understand the concepts, sendmail is responsible for handling the incoming and outgoing mail. Dovecot is what allows the users to access their mail stored on the server via the pop3 or imap protocols, and squirrelmail allows them to access the mail via imap using a web interface (for when they are at home or on the road). All three of these are necessary for mail to run properly except squirrelmail (although it is needed for the webmail). Is this correct?

In order to setup this server to accept mail for a domain, I know that I have to have the MX record pointed to its ip address. No problem there.

I am able to connect using imap and send mail from inside the network but I'm having trouble receiving mail from outside the intranet. I have a small hole poked in our sites firewall to allow smtp and http traffic.

I have a couple test accounts setup and can send mail to outside addresses and internal address just fine, but receiving mail seems to have a problem from outside. Are the smtp and http protocols ports the only ones I need open on the firewall? I believe that they are but want to double check the theory.

If I type in an address of username@216.0.0.[redacted] (ip address is not the real address), shouldn't mail come to the server?

Also, any suggestions on an easy to use and fairly secure ldap server (for a central address book) would also be appreciated or do we not need LDAP for a central address book.

P.S. Telling me to RTFM is not helpful. I've read it. If thats all you can say, please don't reply at all. Sorry about this but I've had several rude replies from the internet on so called helpsites. Hopefully this will be different.