No delivery of domain-internal mail

[Chodid]

Hello everybody,

I thought that I finally fixed all the Issues I had but now I encountered a new problem. If I send domain-internal mails they're just not delivered. Mails from the outside world are delivered just fine.

First thing I did was check the log:

Oct 13 13:46:06 srv2050 postfix/smtpd[3174]: connect from srv2050.provider.tld[95.129.49.***]
Oct 13 13:46:06 srv2050 postfix/smtpd[3174]: 8B511134304: client=srv2050.provider.tld[95.129.49.***]
Oct 13 13:46:06 srv2050 postfix/cleanup[3177]: 8B511134304: message-id=<1097677510.2521255441565682.JavaMail.root@srv2050.provider.tld>
Oct 13 13:46:06 srv2050 postfix/qmgr[9329]: 8B511134304: from=<AAA@domain.net>, size=635, nrcpt=1 (queue active)
Oct 13 13:46:06 srv2050 postfix/smtpd[3174]: disconnect from srv2050.provider.tld[95.129.49.***]
Oct 13 13:46:06 srv2050 postfix/smtp[3178]: connect to 127.0.0.1[127.0.0.1]:10024: Connection refused
Oct 13 13:46:07 srv2050 postfix/smtp[3178]: 8B511134304: to=<BBB@domain.net>, relay=none, delay=0.13, delays=0.11/0.01/0/0, dsn=4.4.1, status=deferred (c$

When I did some Forum research on those log entries I found that it's a problem with amavis so I checked the zimbra status using

su - zimbra
zmcontrol status

The result:

Host srv2050.provider.tld
        antispam                Stopped
                zmamavisdctl is not running
        antivirus               Stopped
                zmamavisdctl is not running
        imapproxy               Running
        ldap                    Running
        mailbox                 Running
        memcached               Running
        mta                     Running
        snmp                    Running
        spell                   Running
        stats                   Running

I tried to start amavis:

zmamavisdctl start

it even said "starting amavis... done" but even after that amavis was still not not running.
when I went back into the log files I found the following (those are the last couple of lines):

Oct 13 14:16:11 srv2050 amavis[30965]: No decoder for       .exe  tried: rar, unrar; lha; arj, unarj
Oct 13 14:16:11 srv2050 amavis[30965]: Using primary internal av scanner code for ClamAV-clamd
Oct 13 14:16:11 srv2050 amavis[30965]: initializing Mail::SpamAssassin
Oct 13 14:16:12 srv2050 amavis[30965]: SpamControl: init_pre_fork on SpamAssassin done
Oct 13 14:16:12 srv2050 amavis[30965]: (!)Net::Server: 2009/10/13-14:16:12 Bad fork [Cannot allocate memory]\n  at line 165 in file /opt/zimbra/zimbramon/lib$
Oct 13 14:16:12 srv2050 amavis[30965]: Net::Server: 2009/10/13-14:16:12 Server closing!

I have to admit that I don't really know what to do about that. It seems that the system is lacking RAM?
The server i'm running is virtualized with XEN, it's got 1024 Mb RAM, i'm running Zimbra 6.0.1 Open Source.
Shouldn't 1024Mb be enough for a 3-5 Mailbox Zimbra Setup? I already tried slimming down the usage but at the moment Zimbra is mostly eating up around 1000 Mb.

Thanks for reading this far I hope we come up with a solution for this.
Best regards