su - zimbra

zmlocalconfig -e mailboxd_java_heap_new_size_percent=20

zmmailboxdctl restart

The Java process will not consume twenty percent of the guest memory. If you need to reduce the memory more then you can tune the MySQL database as-well.

You need to sort out your rDNS entries[quote]unknown[192.168.1.3][/quote]

If you would start by letting us know which version of Zimbra you use

su  - zimbra

zmcontrol -v

is this a single or multi server install ?

Why not just recreate the spool directory ? unless your underlying hardware is having issues.

No, the recipient MTAs should not drop your email; though they may score it negatively as they are not listed as MX records. To alleviate that issue you would be best setting up SPF records on your domain(s) listing all your MTAs that are responsible for both receiving and sending email. The alterna...

Sorry [quote]step by step increment of patches for 7.2.1,7.2.2,7.2.3[/quote] threw me as I thought the OP was regarding them all as patches! Thanks for the clarification Quanah.

Take a backup, take another backup and then apply the 7.2.4 upgrade :) It will make all the necessary schema changes through each revision.

Why would you have email delivery issues ? mta3 and mta4 are only being used for outbound delivery, so email destined for your local domains will not be handled by them. Any internal email will be handled directly on the mail stores.

Well, for inbound only add mta1 and mta2 as MX records to the domain. Then for outbound go into the Admin interface -> Global Settings -> MTA and set mta3 as primary and mta4 as fallback.

Or for LB/HA use HA-Proxy.