UPDATE 2020-11-17
Both Aliant and CloudMark have continued to ignore our repeated requests to provide any valid reason for why they blocked all mail from our server for almost a week - and what little response we have received from either organizations has been hopelessly vague, to the point where their responses seem to be deliberately evasive. We did send witten to both that they provide assurances that, unless there was an actual valid reason, they would refrain from blocking legitimate EMail from AT LEAST the organizations we host which provide critical services, - including 3 ChildFind offices, a children's aid society, and a local Meals on Wheels branch - and their response? From CloudMark, nothing but radio silence since we sent them the request over 3 weeks ago - while Aliant refused to provide any assurance, while seemingly trying to pass the buck to CloudMark by claiming that it's totally out of their hands (which seems highly unlikely, unless they also outsource the management of their mailservers themselves to CloudMark).
In their response, Aliant effectively confirnmed the followg: Aliant allows a for-profit US-based company full control over what EMail they do or don't deliver to their customers, including allowing them control over whether Aliant customers can receive EMail from organizations that are local to them; Aliant has no ability whatsoever to override CloudMark's blacklist with its own whitelist - or (much more likely) is unwilling to do so; Aliant is abundantly aware that using CloudMark has, at least in this incident, has had the direct result of preventing Aliant's own customers from receiving a substantial amount of legitimate EMail, that CloudMark has failed to provide any valid explanation for doing so (despite repeated requests going back over a month now), and that CloudMark was glacially slow to correct that issue, taking more than 4 entire days & 3 separate delisting requests from us (plus however many requests Aliant sent to them) - and yet, despite being fully aware of those issues, Aliant intends to continue using Cloudmark's/Proofpoint's service, AND does not intend to take any steps to prevent the issue from reoccurring in future.
If you have concerns regarding this matter, or are encountering similiar issues, Aliant can be contacted at AliantInternetSecurity@bellaliant.ca - while CloudMark can be contacted via support_csi@cloudmark.com.
UPDATE 2020-10-29:
We finally heard back from Aliant, apparently the issue was because our server's IP address had been listed as a source of spam by CloudMark, a spam filtering service which Aliant makes use of. We had already been aware of that issue, and had sent repeated requests to CloudMark to remove our server's IP from their blacklist - or at LEAST provide a proper explanation for why it was blacklisted, so that we could resolve the issue if there actually was one. Unfortunately, despite having made those requests on Thursday, October 22nd, CloudMark failed to address the issue until early on the morning of Monday, October 26th - four days later, which was also the first time we received ANY response from CloudMark whatsoever (and before then, we had only received a single response from Aliant, that Friday, stating that they were looking into the issue, with no follow-up until Monday).
We have asked CloudMark to provide a explanation for why they blacklisted our server, three separate times now, but unfortunately they have repeatedly failed to provide any valid reason for doing so. They first claimed it was because of a report they received of spam EMail sent from our servers - yet the only example they provided was a single EMail from over a month ago,... that was not actually spam, and they then failed to provide any further examples despite our repeated requests. So at this point, all of the information we have access to indicates that they blacklisted our server by mistake, likely due to an EMail message that someone accidentally reported as spam, then acted on it without making any attempt to verify if the reported message was actually spam - and both CloudMark and Aliant exacerbated the issue, by taking 4 days to address or even respond to the issue in any useful way (which Aliant has confirmed is because they only provide Monday-Friday support for their EMail services). We will continue our efforts to get a valid explanation from CloudMark as to why they caused this issue - if we ever receive a response from them, we will post updates here.
ORIGINAL POST:
We're aware that EMails from our server to any Bell/Aliant-hosted EMail is currently being rejected - which also includes EMails to any old Sympatico or NBNet addresses. While the error messages from Aliant's servers don't provide specific details, it appears that they are explicitly/deliberately blocking all mail from our servers, for some unknown reason. Typically, if one network blocks mail from another, it's because they've received spam from yet - that doesn't appear to be the case here. In addition to our normal monitoring of our IP address' "reputation," we have double-checked that the server is not listed in any legitimate anti-spam blacklist (verified via MXToolbox); nor has Aliant sent us any reports of spam received from our servers, nor are we currently experiencing the same issue with any other EMail provider.
Over the last 48 hours, we have repeatedly contacted Aliant to attempt to get the issue resolved - and so far, they have yet to provide any valid reason for blocking mail from our servers. In one of the few responses we did receive, we were told that they issue would be looked into... which was over 24 hours ago, and in that time there has been no further responses, or any sign of anything being done to address the issue.
Unfortunately, as the problem appears to entirely on Aliant's end, we have no way to resolve the issue except to wait for them to fix it - and with the lack of response from them, we have no way of knowing how long that will take. So if you are currently experiencing that issue, the best thing we can recommend is to contact Aliant about it directly - via EMail at abuse@bellaliant.net or AliantInternetSecurity@bellaliant.ca, via telephone at 1-888-214-7896, or on Twitter @Bell_Aliant.
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