There's been quite a bit of discussion here recently about extending SME with a more universally acceptable groupware product than the Horde Suite and I've been looking at Kerio Mailserver as a possible candidate. Kerio isn't free, but it is cheap and works extremely well, so I'm happy to use it if I can integrate it into an SME server without loosing the features of SME that I value...
A first rate file and print server
A secure combined firewall and web-cache
A management interface that even I can understand.
To get Kerio working I began by disabling the standard SME services that occupy ports 25, 110, 119, 143, 465, 563, and 995 using the Service Control contribution in Server manager. I should have disabled the webservers on ports 80 and 443 and the LDAP stuff on 389 and 636 as well because Kerio, which is completely self-contained, wants to use all those ports, but I wasn't sure about stopping the webservers or the LDAP servers. I then loaded Kerio with yum and it's rpm package and changed its webserver ports to 8080 and 4430. After adding the kerio server start command to rc.local I now have a fully working server that survives reboots and at least one SME software update run from the server manager. It also allows users to authenticate to the mail server from the SME authorisation database, so no laborious double database entry for new users.
At my low-level of competence this seems a potentially powerful way to get round the difficulties of incorporating some very desirable software packages into the SME structure. In Kerio's case the built in backup system is good enough to consider dealing with SME upgrades by backing up the stores, removing the product [yum remove kerio...], upgrading the server, killing the unwanted services again and then reinstalling Kerio and restoring the backup, but perhaps that won't be necessary - I'll try upgrading to 8 beta over my current 7.4 system later today.
Before getting too caried away, however, I'd like to get some knowledgeable comments on this way of doing things. The obvious questions are...
1. Given that my desired application provides its own services, both standard and secure, for SMTP, POP3, IMAP, LDAP and HTTP, can I safely dispense with those functions from SME, and can I do this by actually removing the components with yum remove?
2. Will it be necessary to carry out a separate operation to alter the template system so as to detach the setup templates for those services that are not required, or can they be left intact?
3. If the answer to (1) is yes, what relationship to the SME firewall do the new components have? Is the system still protected or are the third-party services loopholes?
4. Finally, with an eye on other software products, how far can SME component removal be pushed before the system itself is killed - I know, for example, that I can't turn off MySQL because the user databases are stored in it, but what is the minimum SME structure?
Ed Form