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Can't send emails

  • 5 replies
  • 1 has this problem
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  • Last reply by Stans

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Hi. I bought a new computer and reinstalled Thunderbird on it. The problem is I can receive emails but can't not send them. Here is the error message I get -

Sending of the message failed. An error occurred while sending mail: Outgoing server (SMTP) error. The server responded: smtp687.mel.oss-core.net Off-net-IP Detected.

My mail provider is Dodo. My ISP is Dodo as well. My computer is new and I only have a trial version of McAfee Firewall security Version 21.6 and McAfee VirusScan version 26.1. My OS is Windows 11 Home, Version 21H2. Thunderbird Version is 91.10.0.

I have tried all the steps described on your web-site but nothing worked.

Kind regards. Anna.

Hi. I bought a new computer and reinstalled Thunderbird on it. The problem is I can receive emails but can't not send them. Here is the error message I get - Sending of the message failed. An error occurred while sending mail: Outgoing server (SMTP) error. The server responded: smtp687.mel.oss-core.net Off-net-IP Detected. My mail provider is Dodo. My ISP is Dodo as well. My computer is new and I only have a trial version of McAfee Firewall security Version 21.6 and McAfee VirusScan version 26.1. My OS is Windows 11 Home, Version 21H2. Thunderbird Version is 91.10.0. I have tried all the steps described on your web-site but nothing worked. Kind regards. Anna.
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All Replies (5)

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You need to contact Dodo Support and get the right server settings. I haven't found anything on their website and cannot trust the accuracy of third-party sites. You should also get rid of the trial McAfee products. Windows' inbuilt security has come a long way and will get the job done.

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Hello. I have spoken to Dodo already. I have the correct server settings.

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The solution provided here https://support.mozilla.org/en-US/questions/1285648 explains what the Off-net-IP Detected reply from the server means.

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I've already read that thread. It still does not help me. I still don't know what to do to resolve the issue.

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The Off-net-IP reply is coming from the Dodo SMTP server, and it means you tried using it to send mail while NOT connected to your Dodo internet service. The solution, therefore, is to connect to your Dodo internet service if you wish to successfully use their SMTP server. If you are connected to Dodo, you might be tunneling traffic through a vpn. If you're sure you have no active vpn, then Dodo support needs to investigate why their SMTP server is detecting your internet connection as not their own (Off-net-ip).