Emails to BT Internet recipients delayed (SMTP 421 Too many messages)

Issue

Users with IMAP mailboxes hosted on one.com are getting 421 bounces when sending emails to BT Internet customers:

This is the mail system at host mailrelay5.public.one.com.

####################################################################
# THIS IS A WARNING ONLY. YOU DO NOT NEED TO RESEND YOUR MESSAGE. #
####################################################################

I'm sorry to have to inform you that your message has not yet
been delivered to one or more recipients. It's attached below.

<This email address is being protected from spambots. You need JavaScript enabled to view it.> delayed: btinternet.com->MX:
421 Too many messages (1.5.7.1) from 91.198.169.199
Reporting-MTA: dns; mailrelay5.public.one.com
Received-from-MTA: smtp; [192.168.3.86] (81.133.42.155)
Original-Envelope-Id: 6a014cd9-a323-11e5-be90-b82a72d03b9b
Arrival-Date: Tue, 15 Dec 2015 12:16:26 +0000

Final-Recipient: rfc822; This email address is being protected from spambots. You need JavaScript enabled to view it.
Action: delayed
Status: 5.4.7 (Message could not be delivered in the allotted time frame)
Remote-MTA: dns; btinternet.com->MX
Diagnostic-Code: smtp; 421 Too many messages (1.5.7.1) from 91.198.169.199

Emails do get delivered eventually, but after few hours delay.

DELL SonicWALL - get AirPlay and DLNA working between bridged LAN and WLAN

Setup

• DELL SonicWALL NSA 220 wireless-N
• LAN and WLAN interfaces Bridged (on the same subnet)

Issue

• Streaming protocols that rely on multicast (such as Apple Bonjour/AirPlay and DLNA/UPNP) don't work between devices that span LAN and WLAN zones.
• If all devices are either on Wireless or Wired part of the network, everything works fine.

On residential routers you would normally expect such streaming protocols to work between LAN and WLAN with no additional configuration, but because SonicWALL is a business grade firewall, it needs some additional configuration to allow multicast traffic between wired and wireless clients.

Kunena Forum - You are banned until Today

Issue

After restoring a Joomla website from a backup, all users logged on to a Kunena Forum are greeted with "You are banned until Today" message...

Fix 'Leverage browser caching' Google Webmaster Tools warrning

Google Webmaster Tools "Leverage browser caching" warning can be resolved by adding following to the .htaccess file on your (Apache) web server:

## Browser caching ##
<IfModule mod_expires.c>
ExpiresActive On
ExpiresByType image/jpg "access 1 year"
ExpiresByType image/jpeg "access 1 year"
ExpiresByType image/gif "access 1 year"
ExpiresByType image/png "access 1 year"
ExpiresByType text/css "access 1 month"
ExpiresByType application/pdf "access 1 month"
ExpiresByType application/x-javascript "access 1 month"
ExpiresByType application/javascript "access 1 month"
ExpiresByType application/x-shockwave-flash "access 1 month"
ExpiresByType image/x-icon "access 1 year"
ExpiresDefault "access 2 days"
</IfModule>
## Browser caching ##