「メッセージを送信できませんでした メールの送信中にエラーが発生しました サーバーからの応答:Messenge deferred」 というダイアログ（アラート）が頻繁に出てくるので迷惑。 「サーバーからの応答:Messenge deferred」とは何か? 保護の設定:STARTTLS、SMTPも含め、いろいろと解決策を摸索したが駄目だった。 TLS1.2に対応 送信時のポート:587

The dialog (alert) saying, 'Could not send the message. An error occurred while sending the email. Response from the server: Message deferred' keeps appearing frequently, which is annoying. What does 'Response from the server: Message deferred' mean? I tried various solutions, including security settings: STARTTLS, SMTP, but they didn’t work. Supports TLS1.2. Port when sending: 587.

This a response from the server, not from thunderbird. It generally indicates the server is having problems delivering messages. The message was successfully sent, so there is nothing for you to do. If this is happening, regardless of recipient, I suggest you contact your email provider as they administer the server.

Thank you,david.

I'll try contacting my provider. However, my provider, IIJmio, has terrible customer service. The chat support is poor, and their email responses are nonsensical. I can't even get through to them by phone.

Have you considered switching to a more reliable one, such as gmail, outlook, gmx, or others? This might be a good time to consider it. I wish you well in resolving this.

Thank you, David. I use Gmail and Outlook for my personal business. However, I use Thunderbird on my personal PC. Should I switch entirely to Outlook?

My concern was only that I felt you might have a better email experience with a bigger, more popular, email provider. Among the free ones, I like Outlook because it has a good web interface. I have had a free Outlook account for over 15 years with never a problem. But that's also true for my Gmail and Gmx accounts. Of the three, I prefer Outlook. From your past experience with your current email provider, my guess is you will get better support from any of the popular email providers. I wish you well.

Thank you, David. I'm thinking of switching to Outlook. I don't want any more hassle.

Thank you, David. I'm thinking of switching to Outlook. I don't want any more hassle.

I concur. Life is too short to attempt to make things work when there are better alternatives.