[sra]

I've used CommuniGate Pro as a mail server for many years, but I think OS X Server mail has matured enough that there's no reason to rely on third party software for this any more. I have a new machine that I intend to replace my old XServe with, but I don't know how to migrate the mail database, which CommuniGate keeps in a rather different format from OS X Server (I think). There's only one mail account on this system, and it's easy enough to copy the CommuniGate directory with the (masses of accumulated) mail onto the new machine, but how do I import all that mail into an account on the new OS X Server system?

--

Steve Anderson

[besson3c]

I would definitely stop thinking of this switch as being to "OS X Server Mail". AFAIK OS X Server just uses Dovecot IMAP and Postfix and provides a GUI for these things. Think of this at a lower level, learn about what mail format CommuniGate uses and will export to, and assuming you want to use Dovecot's dbox format, find ways to convert from one to the other. Decide where the mail store will live, how it will be backed up, how much disk space you'll need. Start researching Dovecot so that you are familiar with it. Setup a test server using a hand built version of Dovecot or the one rolled into OS X and do a dry run of your mailbox import. Make sure that Dovecot is configured appropriately. You probably want to set it up to support:

- SSL and TLS authentication over port 993 using an SSL cert
- A configurable amount of processes/connections (OS X Mail and the iPhone eat up a ton)
- server side filtering/rules so that you can filter junk messages into a junk folder

If you are going to run web-based email access you'll want to test those clients, perhaps support running your IMAP server(s) on port 143 and setup firewall rules to only allow access from your Webmail server. Run imapproxy.

You'll also need to run a MTA such as Postfix (which I believe OS X Server uses) to deliver message to your store. Look into:

- Configuring for spamhaus and spamassassin support
- I believe OS X Server runs amavisd, look into whether you want to use it in conjunction with a virus checker such as clamav
- Decide whether you want to support DKIM, greylisting, other anti-spam techniques
- Learn all of the queue management tools provided by the MTA, learn about your mail spool
- password authentication for outbound mail
- support for TLS, decide whether you want to support SSL (you probably don't)

Configure your firewall appropriately. Learn how to find message IDs in your logs so that you can trace delivery problems. Learn how to find the envelope sender address in the full headers to a message, as well as the message ID.

There is a lot to running a mail server. Simply looking for a clicky clicky solution will get you into trouble if you don't understand this, I guarantee this, you don't want to go this route. I have customers that have done this and have created serious headaches for themselves.

[besson3c]

If you are definitely wanting to run your own mail server, I would definitely outsource the delivery part of this to somebody else using the Postfix "relayhost" directive unless you are comfortable with this, and you need to be if you don't want your server put on every black/blocklist in existence, business would be affected if mail delivery was halted, you aren't 101% confident in your backup plan, you don't have a disaster recovery plan, etc.

[sra]

I'm sure this is very good advice in general, but my question really is a lot simpler. CommuniGate stores mail in the traditional .mbox format; an account has a hierarchical organization with X.folder directories, each containing a number of separate Y.mbox files (and perhaps some further layers of Z.folder directories). What I want to know is how to import these .mbox files into a mail account established in OS X Server's Mail service.

I've been managing the server for a number of years, and while I certainly don't know a lot about Mail internals, I do know enough about overall server administration to stay out of most trouble.

[besson3c]

Originally Posted by sra 

I'm sure this is very good advice in general, but my question really is a lot simpler. CommuniGate stores mail in the traditional .mbox format; an account has a hierarchical organization with X.folder directories, each containing a number of separate Y.mbox files (and perhaps some further layers of Z.folder directories). What I want to know is how to import these .mbox files into a mail account established in OS X Server's Mail service.

I've been managing the server for a number of years, and while I certainly don't know a lot about Mail internals, I do know enough about overall server administration to stay out of most trouble.

That's exactly the thinking of some of my customers, which has worked great until the shit has hit the fan, at which point a major amount of stress culminated (on multiple occasions).

Dovecot does support mbox (MailboxFormat - Dovecot Wiki), so in theory you could make this switch. The more you can learn out of my above list, the better. Email is not something I would recommend just trusting to point-and-click, just speaking personally...