Server and System Status

Shaw Communications Inc. and their mail filtering sub-contractor (Cloudfilter/Cloudmark) are again delaying, and now even bouncing, email sent to shaw.ca addresses. However, we have no way of communicating with Shaw mail server admins, so we cannot talk to them about how their filtering practices are non-standard and unpredictable.

Our mail server is still/again not in any of the 250 major blacklists that we monitor, so it is unclear why Shaw/Cloudfilter are causing this problem. If you are a Shaw customer, we strongly recommend that you contact Shaw and complain. We also recommend that you do not forward your email to any addresses on their domain.

Update, 2021-07-13 15:45 (PDT): Bounce messages will contain this line, or something very similar to it:

host shw-central.mx.a.cloudfilter.net[3.96.81.40] refused to talk to me: 421 shw-ibgw-4001a.ext.cloudfilter.net cmsmtp too many sessions from 178.62.195.26 AUP#CNCT

Normally bounce messages can be easily deciphered, but even we don’t know what this means or how it makes any sense.

As of Sunday 6 June 2021 (Pacific Time), emails to shaw.ca are being delayed. This problem may also be affecting other domains owned by Shaw Communications Inc., but at this point we’re only aware of the issue affecting email to shaw.ca

The problem appears to be that Shaw has changed their MX record to point to a new, external mail filtering company. (The change is new; the mail filtering company is not new.) All emails to shaw.ca are being temporarily deferred, rather than hard-bounced. It’s unclear why this is, as our mail server’s IP address is not in any major blacklists of the approximately 250 that we regularly monitor. There is also no notice on Shaw’s “Service Updates & Outages” page, and no notification was received by Shaw customers of a planned outage.

We will continue to monitor this situation and, if we can, take any action to work around Shaw’s action and the unavailability of their mail system at the moment. If you have any questions in the meantime, please contact NinerNet support. If you yourself are a Shaw customer, we strongly recommend you contact them and voice your displeasure at your email being delayed and/or blocked.

Update, 2021-06-07 15:00 (PDT): We submitted two support requests to the company to which Shaw outsources their email, but they have been no help, suggesting that we have to contact Shaw directly. However, since they’re blocking our email and they don’t seem to have any kind of a corporate website, that’s rather difficult.

After our last reply to a ticket at 14:23 we checked the mail server to confirm that the copies to Shaw were blocked, and we found that almost all of the queued emails to shaw.ca addresses had been cleared; a few moments later all had been cleared and delivered.

So it seems that this issue has been resolved. However, we have had no contact from Shaw, so without an explanation for why their email stopped working we can’t be sure this won’t happen again.