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Out of nowhere, starting this morning, I am unable to send emails from Thunderbird

  • 11 replies
  • 9 have this problem
  • 4 views
  • Last reply by MGN21

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I have been using Thunderbird as my default email for years and have run into my share of issues. Out of nowhere, starting this morning, I am unable to send emails from Thunderbird at all. I spent about 2 hours on the phone with my service provider trying to figure it out. The unfortunate conclusion I have come to, is that unless you can fix this issue for me, I will be using Outlook going forward. Let me be clear, I HATE OUTLOOK! but I am running out of options other than to throw away the email address I have been using since about 1990.

This is the message I get when the email does not send. This particular one was to trs.ky.gov, but it doesn't matter who the recipient is, the only ones that don't get this message are those I send to myself.

Your message contains invalid characters (bare line feed characters) which the email servers at trs.ky.gov don't support. reb Office 365 julie.soard 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.

Was this helpful? Send feedback to Microsoft.

More Info for Email Admins Status code: 550 5.6.11

This error occurs when the email program or device used to create or send an email message adds bare line feed characters into the message. When bare line feed characters are included in a message, the SMTP protocol chunking feature is required to transmit the message between email servers. Chunking uses the SMTP protocol BDAT command, but the recipient's email server doesn't support the BDAT command.

To fix the issue, the sender should send the message using an email program or device that doesn't add bare line feed characters to messages. Most modern email programs don't add bare line feed characters.

If the sender is using a device like a fax machine, printer, or scanner, it's likely an older model that doesn't support the SMTP protocol BDAT command. To fix this error, you'll need to replace the device with a newer model that supports the BDAT command. The industry standard recommendation to support SMTP chunking was published in 1998 so most devices manufactured during the last decade support this feature.

Another option is for the email admin at the recipient's domain to upgrade their email servers to servers that support the SMTP protocol BDAT command. Most modern email servers support BDAT; however, some free and older email servers don't support it.

For more information see Fix email delivery issues for error code 5.6.11 in Office 365.

Original Message Details Created Date: 8/2/2022 9:35:48 PM Sender Address: reb@isoc.net Recipient Address: julie.soard@trs.ky.gov Subject: Fwd: documents for retirement

Error Details Reported error: 550 5.6.11 SMTPSEND.BareLinefeedsAreIllegal; message contains bare linefeeds, which cannot be sent via DATA and receiving system does not support BDAT DSN generated by: SN6PR08MB5327.namprd08.prod.outlook.com

I have been using Thunderbird as my default email for years and have run into my share of issues. Out of nowhere, starting this morning, I am unable to send emails from Thunderbird at all. I spent about 2 hours on the phone with my service provider trying to figure it out. The unfortunate conclusion I have come to, is that unless you can fix this issue for me, I will be using Outlook going forward. Let me be clear, I HATE OUTLOOK! but I am running out of options other than to throw away the email address I have been using since about 1990. This is the message I get when the email does not send. This particular one was to trs.ky.gov, but it doesn't matter who the recipient is, the only ones that don't get this message are those I send to myself. Your message contains invalid characters (bare line feed characters) which the email servers at trs.ky.gov don't support. reb Office 365 julie.soard 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. Was this helpful? Send feedback to Microsoft. More Info for Email Admins Status code: 550 5.6.11 This error occurs when the email program or device used to create or send an email message adds bare line feed characters into the message. When bare line feed characters are included in a message, the SMTP protocol chunking feature is required to transmit the message between email servers. Chunking uses the SMTP protocol BDAT command, but the recipient's email server doesn't support the BDAT command. To fix the issue, the sender should send the message using an email program or device that doesn't add bare line feed characters to messages. Most modern email programs don't add bare line feed characters. If the sender is using a device like a fax machine, printer, or scanner, it's likely an older model that doesn't support the SMTP protocol BDAT command. To fix this error, you'll need to replace the device with a newer model that supports the BDAT command. The industry standard recommendation to support SMTP chunking was published in 1998 so most devices manufactured during the last decade support this feature. Another option is for the email admin at the recipient's domain to upgrade their email servers to servers that support the SMTP protocol BDAT command. Most modern email servers support BDAT; however, some free and older email servers don't support it. For more information see Fix email delivery issues for error code 5.6.11 in Office 365. Original Message Details Created Date: 8/2/2022 9:35:48 PM Sender Address: reb@isoc.net Recipient Address: julie.soard@trs.ky.gov Subject: Fwd: documents for retirement Error Details Reported error: 550 5.6.11 SMTPSEND.BareLinefeedsAreIllegal; message contains bare linefeeds, which cannot be sent via DATA and receiving system does not support BDAT DSN generated by: SN6PR08MB5327.namprd08.prod.outlook.com

All Replies (11)

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I'm no super geek, but are you using an external editor, such as MS Word, and then pasting into compose window? Are you using HTML messages? I'm guessing some non-Thunderbird product is involved that is causing the unwanted characters.

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This is happening to a lot of people are the moment including me, just started today and I have not changed anything on how I compose emails. Microsoft say it's not their fault yet only appears to happen with users who use Thunderbird + 365 server

https://support.mozilla.org/en-US/questions/1384816#answer-1525256

Modified by vl.turbo.88

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i am also having this problem

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In my case it was my antivirus outbound scan that was causing the issue. See my post in the link provided by vl.turbo.88

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I am having the same problem.

It appears that Avast will scan my mail before I send it out, and add a line at the end of my mail. After I turn off mail protection, I can send mail out.

If you are having the same problem, try turning off you antivirus and see if it works.

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I Followed the interactions that nszmnsky and tfs_manng gave I use AVG Anti virus I went into Email Shield and turned off "Add signature to the end of sent emails" and this looks to have fixed this problem thank you both for the help!!

nszmnsky said

In my case it was my antivirus outbound scan that was causing the issue. See my post in the link provided by vl.turbo.88

tfs_manng said

I am having the same problem. It appears that Avast will scan my mail before I send it out, and add a line at the end of my mail. After I turn off mail protection, I can send mail out. If you are having the same problem, try turning off you antivirus and see if it works.
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From my I.T. guy: You’re using an email app that’s not supported by Microsoft. Microsoft has been slowly blocking the communication transit protocol between old email apps and their servers.

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Your IT guy is misinformed. Microsoft does not block email apps from other providers.

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Your IT is indeed wrong. The problem is resolved. It was created by my AVAST virus protection that was adding characters to outgoing emails when it scanned them. This caused my emails to be rejected by some but not all servers. If you have this issue, there is a setting in AVAST that allows you to disable incoming and outgoing email scans. Disable that and your email will flow freely again.

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Thanks guys! My I.T. guys likes to spend our money! I use AVG, which I believe is owned by the same company as AVAST now. I will look into this fix and do it, and get back to you. Thanks for your help! Mike

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That did it!!! Thanks!