What Zimbra do with Mails?

[devent]

Hallo
in the past I used my own imap-server (dovecot), postfix, procmail, fetchmail and so, for my Emails. I'm not quite sure what Zimbra can do for me.
Zimbra can store my mails, addresses, calendars and so on on my server so it'll evailable for me world wide. That I understood. But Zimbra isn't an email-Server?

Do I still need to configure my email-server (dovecot, postfix, procmail, fetchmail) to send and receive emails? I have email accounts on gmx, gmail and others, how I use this with Zimbra?

[phoenix]

That's correct, Zimbra isn't an email server it's a complete collaboration suite which includes an email MTA (postfix). Search the forums for details or check the product documentation or the wiki for details.

[dkarp]

But you should also note that you'd run Zimbra instead of your existing dovecot/postfix/etc. setup. One of the things that Zimbra is is a mailstore.

[devent]

Can you give me a nice howto how I can configure the zimbra postfix to use a gmail or gmx account for sending mails?

And one more question. I have also an apache server for a webpage on the same server. Sure I can use for Zimbra another port and the port 80 for the apache. But can I use the postfix from zimbra to send mails from the apache or do I need another postfix? I think I can just enter in the php.ini for the sendmail location the location of the postfix in /opt/zimbra

Edit:
I try to configure postfix after this tutorial: Gmail on Home Linux Boxes using Postfix and Fetchmail
but zimbra always reseted my changes in the /opt/zimbra/postfix/main.cf
the transport_maps, disable_dns_lookups and relayhost are reseted, how I can change that?

[devent]

I try to configure the zimbra postfix with this tutorial:
Gmail on Home Linux Boxes using Postfix and Fetchmail
But zimbra always changes my main.cf after server restart.
relayhost, disable_dns_lookups and transport_maps are reseted. How I can change that?