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(bare line feed characters) which the email servers don't support.

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I cannot send or forward E-mails using Thunderbird. It started about 10 days ago. The same error occurs when sending E-mails to Gmail.com, Msn.com and other accounts and E-mails addresses. I can send E-mails to myself and then use my cell phone

The following is part of the error message: Thanks.

Your message to en_fuego18@hotmail.com couldn't be delivered. Your message contains invalid characters (bare line feed characters) which the email servers at hotmail.com don't support. rsinclai Office 365 en_fuego18 Action Required Recipient

Bare line feeds unsupported

How to Fix It It appears that your email program added invalid characters (bare line feed characters) into your message when you sent it. Try using a different email program to send your message. If the problem continues send this non-delivery report (NDR) message to your email admin for assistance.

I cannot send or forward E-mails using Thunderbird. It started about 10 days ago. The same error occurs when sending E-mails to Gmail.com, Msn.com and other accounts and E-mails addresses. I can send E-mails to myself and then use my cell phone The following is part of the error message: Thanks. Your message to en_fuego18@hotmail.com couldn't be delivered. Your message contains invalid characters (bare line feed characters) which the email servers at hotmail.com don't support. rsinclai Office 365 en_fuego18 Action Required Recipient Bare line feeds unsupported How to Fix It It appears that your email program added invalid characters (bare line feed characters) into your message when you sent it. Try using a different email program to send your message. If the problem continues send this non-delivery report (NDR) message to your email admin for assistance.

All Replies (6)

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Hello there rscinclai. We have read your message. We try to help you.

Your email has be bounced back. Maybe by a firewall or server.

This 550 error says that your message that you have send that been going to the recipient inbox. Is not allowed to go there.

It might be a bug or a situation to solve it with parameters to set there value. If this situation cannot be solved with this setting change it s recommended to reinstall the Thunderbird Software and follow the steps in the site info that is send with this mail to you.

The site info. https://support.mozilla.org/nl/questions/1386086#answer-1527437

https://support.mozilla.org/en-US/kb/cannot-send-messages

Greetings Firefox volunteer.

Edeziri site na Googlethunderbird

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I want to use Thunderbird Email app which I have used for many years. Is there a Thunderbird add-on that can remove the bare line feeds before the written E-mails are sent or forwarded? I can send E-mails to myself and forward L.L. Bean and Wild Wings E-mails All others fail because of BLFs errors. This problem only started about 2 weeks ago. I do not want to use a browser based E-mail application. They are clumsy to use.

Thank you.

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What is your anti-virus software?

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Try to start Windows 10 in safe mode with networking enabled.

Does the problem go away?

Windows safe mode disables anti-virus software. This is a troubleshooting step, not a solution.