A side-effect of yesterday’s Internet Connectivity Issues was that our backup mail systems were subjected to a near 24 hour real world test, which they passed with flying colours.  All our Backup MXs performed exactly as intended without compromising the service availability for any of our mail customers even when running under loads of tens of thousands of messages.

What’s a Backup MX?

In the event of one of our primary mail servers going offline, all mail traffic is automatically transferred to one of our backup servers, called a Backup MX.  This switchover is seamless and is completely transparent to both the sender and the recipient.  The Backup MX will then store all incoming messages until such time that primary server is online again, at which point all messages are automatically sent to it.

All NamesAndSpace hosting accounts that include mail services automatically come with a Backup MX facility so that in the event of our the N&S mail server going offline, you don’t lose any messages.

Changes to Spam Filtering

At the peak of yesterday’s traffic,  our Backup MXs were storing in excess of 20,000 messages pending delivery.  Needless to say, the vast majority – more than 90% – of these were spam or junk mail.  In light of this, we are revising our spam filtering systems to purposefully intercept and eliminate a substantial proportion of spam messages before they reach individual e-mail accounts.

Our spam filtering systems work on a score-based.  Every message passing through our servers is subject to a series of checks, each of which is designed to test a particular aspect or property of the message for validity.  If a check fails, then the a value is added to the message’s spam score.  Once the score reaches a threshold value – the spam mark threshold – , the message is considered to be a spam or junk message.  If the score reaches a higher threshold value, then the message will automatically be deleted.

The changes we have implemented are two-fold.  Firstly, we have lowered the bar of the spam mark threshold.  This will have the effect of a higher proportion of messages being marked as being Spam.

The second change is more proactive.  One of the checks we employ is called a Blacklist Lookup where the address of the sending e-mail server for each message is checked against an online list of known spamming servers.  If the sender is a known spammer, then the message in question will now be automatically intercepted and deleted.

Since we implemented these changes last night, the amount of spam messages reaching individual mail boxes has reduced significantly.  These changes were not made solely in light of yesterday’s issues as we had been planning to introduce them in the near future.  If anything, yesterday merely served to accelerate their introduction.

False Positives

In the highly unlikely event you may believe that some valid messages are being marked as spam – otherwise known as a false positive – please contact our Support Team via http://www.acssupport.co.uk for further assistance.

As always, if you have queries regarding any product or service supported by ACS Limited, please do not hesitate to contact our Support Team via http://www.acssupport.co.uk.

We’re experiencing a few intermittent connectivity problems with our office Internet connection this morning.  This in turn is delaying some messages being sent to any e-mail address at appliedconsultancy.com.  At present, we believe these issues to transitory and will should be resolved shortly.

These connection issues do not impact nor affect our NamesAndSpace (N&S) hosting servers, nor any of our own websites like ACS Support. All of our N&S servers are located within resilient data centres that incorporate multiple levels of redundancy.

Update 14:35

We’re still experiencing internet connection problems at our office which is impacting on our incoming messages.  At the last count, there were over 3,000 messages still waiting to arrive (95% of which will be spam).  If you have any questions or queries, please submit them via our support website http://www.acssupport.co.uk which remains fully operational and unaffected by these problems.

Update Wednesday 10:00

The internet connectivity issues have now been resolved and all outstanding messages have now filtered through to our mail systems.  If you sent a message to any e-mail address at appliedconsultancy.com it should now be with the intended recipient.  As with out NamesAndSpace hosting accounts, all our e-mail systems utilise Backup MXs (mailservers) to ensure that no valid (see below) mail traffic is lost.

As some of our support customers may be aware, we had a problem earlier today with the e-mail feed for our support ticket facility.  In correcting the issue, some old updates were re-registered causing duplicate e-mail alert messages to be sent out.

If you were a recipient of these duplicate or out of date messages, we apologise for any inconvenience or confusion their arrival may have caused.  We have now implemented a number of extended measures to mitigate the possibility of this issue from reoccurring.

Our support team fully investigated this problem, and it was sourced to an old enemy: spam.  Out of all the messages we receive through the support e-mail address (support [at] appliedconsultancy [dot] com *) less than 2% are actually support related.  In this instance, a deluge of SPAM messages, mostly Russian in origin and content and with sizable attachments had filled up e-mail account.

Despite some progress in recent months, Spam continues to account for at least 80% of all e-mail traffic.  Increasingly, we are seeing spam messages containing some form of malware (Virus, Spyware, etc.) as an attachment.  Our recommendation on handling suspect e-mail messages remains the same: If you don’t recognise the sender,or have any doubts, don’t open the message and delete it.

* The support e-mail address is only accessible by registered ACS Support account holders and through their nominated e-mail addresses.  Any messages sent to this address from an unknown e-mail accounts are automatically deleted.