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<p>Andrew,</p>
<p>This is likely off topic for this list, but anyway, since I live on the edge...</p>
<p>By my count there is only 3 not 10 mechanism lookups (and show me an implementation that actually stops at 10), I'm not so sure they should be counting the includes includes/a/aaaa's either, only the include itself, as includes are typically out of your control (it has been a very long time since I read that RFC so may be wrong)</p>
<p>Anyway, if that was the issue, it would have surfaced long before now surely.</p>
<p>If I was a betting man, I'd say DNS caching is the cause, if I was a betting man, I'd also be betting someone didnt drop a TTL when preparing for the change, so will have to wait till records refresh.</p>
<p>Of course all this is assumption because OP never posted the actual error message.</p>
<p>Cheers</p>
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<p id="reply-intro">On 19/10/2021 09:07, Andrew Oakeley wrote:</p>
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<p class="v1MsoNormal">Hi,</p>
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<p class="v1MsoNormal">If I was you; I would start by fixing your SPF.</p>
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<p class="v1MsoNormal">This will show you the errors</p>
<p class="v1MsoNormal"><a href="https://mxtoolbox.com/SuperTool.aspx?action=spf%3aheartland.com.au&run=toolpage" target="_blank" rel="noopener noreferrer">https://mxtoolbox.com/SuperTool.aspx?action=spf%3aheartland.com.au&run=toolpage</a></p>
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<p class="v1MsoNormal">Andrew</p>
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<p class="v1MsoNormal"><strong><span style="mso-fareast-language: EN-AU;">From:</span></strong><span style="mso-fareast-language: EN-AU;"> AusNOG <ausnog-bounces@lists.ausnog.net> <strong>On Behalf Of </strong>Christopher Scholfield<br /><strong>Sent:</strong> Tuesday, 19 October 2021 7:04 AM<br /><strong>To:</strong> 'AusNOG Mailing List' <ausnog@ausnog.net><br /><strong>Subject:</strong> [AusNOG] Anyone knowledgeable from Mimecast here who can contact me off list?</span></p>
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<p class="v1MsoNormal">Yesterday we changed mail filters, Mimecast is the only email provider that has been rejecting our emails due to SPF problems for the last 20 odd hours. Mimecast technical support has told me their customers who aren't getting our emails need to contact them so their tech support can explain how to bypass their mail filters for our mail server.</p>
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<p class="v1MsoNormal">I'd rather work with someone at Mimecast to resolve the cause of the problem.</p>
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<div id="signature">-- <br />
<p>Regards,<br />Noel Butlerimplimentation</p>
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<p><span style="font-size: 9pt;"><span style="font-family: arial,helvetica,sans-serif;">This Email, including attachments, may contain legally privileged information, therefore at all times remains confidential and subject to copyright protected under international law. You may not disseminate this message without the authors express written authority to do so. If you are not the intended recipient, please notify the sender then delete all copies of this message including attachments immediately. Confidentiality, copyright, and legal privilege are not waived or lost by reason of the mistaken delivery of this message.</span></span></p>
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