I'm not a thunderbird user, but it looks like the error is
occurring because you are forwarding the email as an attachment. This
listserv does not allow any file attachments (for security purposes), so
maybe that is true for the server you are forwarding messages to as well.
It could be that just specific formats (like *.eml) are not accepted.
Forwarding the message "inline" might solve this.
This thread has some discussion about that error and suggestions for
changing your default settings:
https://support.mozilla.org/en-US/questions/1495816
Hope that helps,
HH
On Thu, Jan 22, 2026 at 2:58 PM GS lists@gregschmitz.com wrote:
Is anyone else having problems with the GBW listserv? When I try to
forward a message using the Thunderbird email program, it fails to
forward and shows this warning:
"Sending of the message failed.
An error occurred while sending mail. The mail server responded:
Attached file 'ForwardedMessage.eml' has disallowed extension. Please
check the message and try again."
The problem only occurs with some messages went by the GBW listserv.
Thanks for any insights.
--greg schmitz
GBW: The email list for GBW member communications
To post a message, send an email to gbw@list.guildofbookworkers.org
To unsubscribe by email, write to gbw-leave@list.guildofbookworkers.org
When replying, please edit your Subject line so it is more specific than
"Re: Contents of GBW digest..."
For info about the list or to change your settings, visit:
https://list.guildofbookworkers.org/list/gbw.list.guildofbookworkers.org
List subscribers who wish to manage their list specific settings will also
need to register. Registration is NOT required to post/receive list
messages. To register, go to: https://list.guildofbookworkers.org/register
For problems, contact the Communications Chair:
communications@guildofbookworkers.org
I'm not a thunderbird user, but it looks like the error is
occurring because you are forwarding the email as an attachment. This
listserv does not allow any file attachments (for security purposes), so
maybe that is true for the server you are forwarding messages to as well.
It could be that just specific formats (like *.eml) are not accepted.
Forwarding the message "inline" might solve this.
This thread has some discussion about that error and suggestions for
changing your default settings:
https://support.mozilla.org/en-US/questions/1495816
Hope that helps,
HH
On Thu, Jan 22, 2026 at 2:58 PM GS <lists@gregschmitz.com> wrote:
>
> Is anyone else having problems with the GBW listserv? When I try to
> forward a message using the Thunderbird email program, it fails to
> forward and shows this warning:
>
> "Sending of the message failed.
> An error occurred while sending mail. The mail server responded:
> Attached file 'ForwardedMessage.eml' has disallowed extension. Please
> check the message and try again."
>
> The problem only occurs with some messages went by the GBW listserv.
>
> Thanks for any insights.
>
> --greg schmitz
> GBW: The email list for GBW member communications
>
> To post a message, send an email to gbw@list.guildofbookworkers.org
> To unsubscribe by email, write to gbw-leave@list.guildofbookworkers.org
>
> When replying, please edit your Subject line so it is more specific than
> "Re: Contents of GBW digest..."
>
> For info about the list or to change your settings, visit:
> https://list.guildofbookworkers.org/list/gbw.list.guildofbookworkers.org
>
> List subscribers who wish to manage their list specific settings will also
> need to register. Registration is NOT required to post/receive list
> messages. To register, go to: https://list.guildofbookworkers.org/register
>
> For problems, contact the Communications Chair:
> communications@guildofbookworkers.org
