Please don’t follow these steps, as you’ll get authentication problems when authentication over SMTP. Have a look at this post.

How to configure Zimbra to download SpamAssassin antispam updates using a proxy.

Make configuration change

Start by editing this file.

/opt/zimbra/.bashrc

Then add the following 2 lines. Change them to the hostname or ip address and port of your proxy server.

export https_proxy="http://proxy.example.org:3128"
export http_proxy="http://proxy.example.org:3128"

And save the file.

Test SpamAssassin update

Run the following command as zimbra user. If it doesn’t display an error, you’re good.

. /opt/zimbra/.bashrc; /opt/zimbra/libexec/zmsaupdate

Automatic daily updates

Each night, your zimbra installation will attempt to update the spamassassin definitions at midnight + 45 minutes. The update is triggered by the following crontab entry.

#
# Spam rule updates
#
45 0 * * * . /opt/zimbra/.bashrc; /opt/zimbra/libexec/zmsaupdate

There is no need to create this entry. It should already exists as part of the default zimbra installation.

You want to update ClamAV using a proxy?