Test emails being quarantined by Microsoft

  • Resolved sarahsas

    (@sarahsas)


    1 year, 1 month ago

    Hello, I work with a web dev company and we use your SMTP tool in conjunction with Postmark on all our sites. In the past 4 months or so, all the test emails have been being quarantined by Microsoft’s absurdly high spam filters, and none of the traditional methods of overcoming this (i.e. whitelisting IP addresses) seems to have any effect. I’ve been working with Microsoft for a while and their last correspondence to me says the following:

    I was able to check the issue internally and have confirmed that this is an expected behavior for emails being marked as High Confidence Phishing due to the Secure by default in M365. As stated in?Secure by default in Office 365 | Microsoft Learn:

    Because Microsoft wants to keep our customers secure by default, some tenants overrides aren’t applied for malware or high confidence phishing. These overrides include:

    • Allowed sender lists or allowed domain lists (anti-spam policies)
    • Outlook Safe Senders
    • IP Allow List (connection filtering)
    • Exchange mail flow rules (also known as transport rules)

    If you want to temporarily allow certain messages that are still being blocked by Microsoft, do so using admin submissions.

    This is why everything we configured are not working. Our only suggestion now is to fix the issue on the sender side.

    I cannot see ANYTHING in your test emails that would make Microsoft think it’s “High Confidence Phishing”, but they are pushing back saying it’s basically your problem not theirs. Have you encountered this before, any solutions?

    We are crippled from setting up and testing any new accounts due to the fact that we can no longer sent test emails that will actually come through ever anymore… help?

Viewing 4 replies - 1 through 4 (of 4 total)
  • Plugin Support Amimul Ihsan Mahdi

    (@amimulihsanmahdi)

    Hello there,

    Email deliverability depends on various aspects and SMTP is one of them. Make sure you have configured SMTP accurately please check SMTP header(From name and email). You can test the spamminess of your email here. In addition, can you please share the email source with the header that is being marked as spam so that we can look further?

    Thank you

    Thread Starter sarahsas

    (@sarahsas)

    Hi @amimulihsanmahdi, I checked the spamminess using your link, it came back 10/10, so that’s not the issue. We use Postmark for SMTP delivery and verify all domains and they are definitely configured correctly, so that’s also not the issue. We know this because regular notifications that are sent from forms in wordpress, for example, will come through fine. It is literally just your plugin’s “SMTP test” email that continually gets quarantined. And it’s marked with “high confidence phishing” by Microsoft’s tools each time, which is the confusing part.

    We have been using this Fluent SMTP/Postmark combination for several years now and this only began occurring with regularity about 4 months ago. And now no tests at all ever come through, they get quarantined every time.

    Is there a way I can privately share with you the header contents of the email rather than posting it in a public form? Please let me know?

    Plugin Support Amimul Ihsan Mahdi

    (@amimulihsanmahdi)

    Hello again,

    You can share the details here. Our team will take a look and get back to you.

    Thank you

    Thread Starter sarahsas

    (@sarahsas)

    Thank you, I have submitted a support ticket.

Viewing 4 replies - 1 through 4 (of 4 total)
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