NinerNet Communications™
System Status

Server and System Status

NC023: Relay server stopped to clean up spam

26 January 2014 13:28:29 +0000

The relay server has been stopped while we clean up a spam outbreak, and identify and block the source. We will post updates here. We expect to have the server back online within the next 30-40 minutes.

Email migration: Update 13

16 October 2013 10:09:43 +0000

Since the migration of many email accounts to the new server, we’ve had reports of email from some regular correspondents (with email hosted outside of NinerNet) to domains hosted on the new server bouncing back to those senders as undeliverable. All of these reports, so far, are about the same improper configuration of Microsoft Exchange mail servers.

A person sending you an email through a mis-configured mail server will receive a bounce message that includes an explanation for the bounce that looks like this:

you@yourdomain.com
nc027.ninernet.net #554 5.7.1 <senderdomain.local>: Helo command rejected: Go away, bad guy (.local).

The problem is the “senderdomain.local” string. In this case “senderdomain” stands in for an actual name — e.g., something that looks like it might be a domain — followed by “.local”. A properly configured mail server that connects to the public Internet is supposed to advertise a “fully-qualified domain name” (FQDN) through the “HELO” (or “EHLO”) command rather than “something.local”, which is not a real domain. Many mail servers, including ours, reject attempts to deliver mail from improperly configured mail servers advertising a “domain” that does not (or cannot) exist. The reason for this is that much spam comes from machines that are improperly configured in this manner. More technical details about this can be read in theĀ Best Practises for Email and Network Operators – Valid HELO domain article.

Your correspondents will likely think that we are blocking their domain specifically (very likely that we are NOT) or that something is otherwise wrong on our mail server. However, it is the other way around; your correspondents experiencing this problem need to talk to their own IT people, perhaps pointing them to this post, as their mail server needs to be reconfigured correctly.

The article Exchange DNS Configuration for Email Delivery includes a number of helpful hints for the Exchange server administrator about how to properly configure an Exchange server to work correctly on the Internet with respect to domains and DNS. About half way down the page are sections entitled SMTP Banner – Exchange 2003 and SMTP Banner – Exchange 2007 that explain how to set the SMTP banner — i.e., the domain that is advertised by the Exchange server when it connects to another mail server to attempt to deliver email. As mentioned previously, this needs to be a proper domain that is resolvable on the Internet, not something that doesn’t exist like “senderdomain.local”.

Our experience is that when an Exchange server is correctly reconfigured, email from that server starts getting through again immediately, and deliveries to other servers that do not block based on this incorrect behaviour are not affected.

Another possible solution to this problem is for the Exchange server to use a smart host, through which all outbound email is delivered to the public Internet. This has a number of advantages, including not having to reconfigure the SMTP banner and the fact that the server administrator doesn’t have to be concerned about their own IP address being added to a block list if (again as a result of mis-configuration) the server inadvertently becomes the source of spam. NinerNet provides this service (relay server / smart host) for USD30 / CAD36 / ZMW165 per month.

Or you could send Microsoft Exchange Server 2007 For Dummies to the sending domain’s server administrator!

Server NC023 maintenance complete

4 May 2013 19:38:02 +0000

Server NC023 went down for maintenance at 19:22 UTC and was back online at 19:32 after successful completion of its maintenance.

Thanks for your patience.

Server NC023 maintenance

3 May 2013 06:37:17 +0000

We will be performing maintenance on server NC023 (commonly known as the relay server) on Saturday, 4 May at 19:00 UTC. This maintenance will take approximately 10-15 minutes, during which time the server will not be accessible.

Server NC023 maintenance completed

14 April 2013 08:11:59 +0000

The maintenance on server NC023 took place between 07:08 and 07:14 UTC, and was completed successfully.

Server NC023 down for maintenance

14 April 2013 07:13:41 +0000

Server NC023 (more commonly known as the relay server) is currently undergoing an upgrade, and will be back up again by approximately 07:25 UTC.

Relay server back online

14 October 2011 14:48:58 +0000

The relay server is once again back online. We apologise for the inconvenience, and are working with the affected client to ensure that this problem is addressed.

Relay server offline

14 October 2011 14:27:28 +0000

The relay server is again offline while we clean up spam. It will be back online again within about half an hour.

Relay server back online

11 October 2011 16:55:57 +0000

The relay server is back online, and the source of the spam has been blocked until that client has re-secured their mail server. Thanks for your patience.

Relay server offline

11 October 2011 16:03:13 +0000

The relay server is offline for a few minutes while we clean up some spam that has been submitted through it. We’ll post an update here when it’s back online.

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General Information:

This blog provides information about the status of NinerNet Communications systems. Dates and times of posts to this blog are in the UTC time zone, and dates and times given for events are also in the UTC time zone, although conversions may be offered for some time zones common to our clients. Please use the World Time Server to ensure accurate conversion of dates and times to your own time zone.

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