This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Cannot forward emails over c. 200K as attachments

  • 4 cavab
  • 0 have this problem
  • 1 view
  • Last reply by Toad-Hall

more options

When I try to forward emails over c. 200K, I get the following error message:

An error occurred while sending mail. The mail server responded: Line length exceeded. See RFC 2821 #4.5.3.1.. Please check the message and try again.

I have researched this error, and it seems it comes from a line length in the email code being >999 characters long without a space. Now, I get my messages from Yahoo imported into Thunderbird; I can forward such messages as attachments in Yahoo, but not in Thunderbird. Whatever the issue, is there a way to change, alter, or override the RFC setting so I can send larger attachments as emails without encountering this error? I've seen hints on the Web that it might be doable given this or that add-on or by something called GWAVA, but I can't effect a solution myself. Any help would be appreciated. Thanks, John- :)

When I try to forward emails over c. 200K, I get the following error message: An error occurred while sending mail. The mail server responded: Line length exceeded. See RFC 2821 #4.5.3.1.. Please check the message and try again. I have researched this error, and it seems it comes from a line length in the email code being >999 characters long without a space. Now, I get my messages from Yahoo imported into Thunderbird; I can forward such messages as attachments in Yahoo, but not in Thunderbird. Whatever the issue, is there a way to change, alter, or override the RFC setting so I can send larger attachments as emails without encountering this error? I've seen hints on the Web that it might be doable given this or that add-on or by something called GWAVA, but I can't effect a solution myself. Any help would be appreciated. Thanks, John- :)

All Replies (4)

more options

If you select email so viewing in Message Pane - click on 'More' and select 'View source'

Is Content-Transfer-Encoding: set as 7bit or 8bit or base 64? eg:

  • Content-Type: text/html; charset=UTF-8
  • Content-Transfer-Encoding: base64

OR

  • Content-Type: text/html; charset=UTF-8
  • Content-Transfer-Encoding: 7bit or 8bit

Does the email you want to forward contain any attachments ?

more options

How long is the 'Subject' line?

In 'View Source' do you notice if there are any parts of header data that exceed line length ?

Modified by Toad-Hall

more options

The source code doesn't contain anything about 7bit, 8bit, or base64. The content type is "Content-Type: text/html; charset=UTF-8". And it doesn't contain attachments-

more options

Lt. Commander Data said

The source code doesn't contain anything about 7bit, 8bit, or base64. The content type is "Content-Type: text/html; charset=UTF-8". And it doesn't contain attachments-

Below : Content-Type: text/html; charset=UTF-8 You should see info: Content-Transfer-Encoding: ?

If you see the actual content of the email in the view source then it will not be base64.

You could post an image which shows the View Source. You can blank out email addresses and anything sensitive.