To set 8bitmime or not?

My company is using a mail gateway in front of the backend mail server.
Both the mail gateway and backend mail server could support
7bit/8bitmime. However, I exprience a problem on the following
scenario:

1. Set both gateway and server support 8bitmime
For that case, we will receive NDR "5.6.1 Body type not supported by
remote host" when sending mail to servers which don't support 8bitmime

2. Set the gateway to support 7bit only.
For that case, the problem on sending mail to 7bit mail server solved.
However, when someone redirect their mails from a 8bitmime enabled
server to our mail server, our mail gateway could not receive it as the
mail was in 8bitmime already.

May I know the common practice of setting mail gateway, 7bit only or
8bitmime? How to handle for the problem in either case?

Thank you!

Eric

Re: To set 8bitmime or not?

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cheng.nospam@gmail.com writes:

> My company is using a mail gateway in front of the backend mail server.
> Both the mail gateway and backend mail server could support
> 7bit/8bitmime. However, I exprience a problem on the following
> scenario:
>
> 1. Set both gateway and server support 8bitmime
> For that case, we will receive NDR "5.6.1 Body type not supported by
> remote host" when sending mail to servers which don't support 8bitmime
>
> 2. Set the gateway to support 7bit only.
> For that case, the problem on sending mail to 7bit mail server solved.
> However, when someone redirect their mails from a 8bitmime enabled
> server to our mail server, our mail gateway could not receive it as the
> mail was in 8bitmime already.
>
> May I know the common practice of setting mail gateway, 7bit only or
> 8bitmime? How to handle for the problem in either case?

Replace your broken software with one that works correctly. I have no idea
what kind of ancient, decrepid dinosaur you are running. All modern mail
servers support 8bitmime, and will automatically reencode mail with 8-bit
content to quoted-printable when sending mail to external servers that claim
not to support 8bitmime.

8-bit mail can be easily converted to 7-bit quoted-printable, and vice
versa. This is not rocket science, and ways to do that have been known for
years. This should not be an issue for any mail server.



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Re: To set 8bitmime or not?

Thanks for the reply. I knew that most of the email system should
support 8bit nowadays, except something like exchange 5.5. When these
mail servers communicating directly, it should not be a problem because
the sender and receipient SMTP server talk directly and they could
negotiate the best encoding methods.

However, when there is a gateway between them, the situation is
different. In my case, the mail gateway is Microsoft IIS 6. It
supports 8-bit MIME in nature. When sending email from my backend to
other Internet SMTP server, it must send through my mail gateway. The
mail will be encoded in 8-bit as IIS supports it. However, when this
8bit message is directed to the destinated server which support 7-bits
only, the destination server will report "5.6.1 body type not
supported...." and close the SMTP conversation. I wonder if this is
the problem of IIS 6 that it could not convert the 8bitmime to 7-bit
quoted-printable, and vice versa.

Re: To set 8bitmime or not?

Thanks for the reply. I knew that most of the email system should
support 8bit nowadays, except something like exchange 5.5. When these
mail servers communicating directly, it should not be a problem because
the sender and receipient SMTP server talk directly and they could
negotiate the best encoding methods.

However, when there is a gateway between them, the situation is
different. In my case, the mail gateway is Microsoft IIS 6. It
supports 8-bit MIME in nature. When sending email from my backend to
other Internet SMTP server, it must send through my mail gateway. The
mail will be encoded in 8-bit as IIS supports it. However, when this
8bit message is directed to the destinated server which support 7-bits
only, the destination server will report "5.6.1 body type not
supported...." and close the SMTP conversation. I wonder if this is
the problem of IIS 6 that it could not convert the 8bitmime to 7-bit
quoted-printable, and vice versa.

Re: To set 8bitmime or not?

This is a MIME GnuPG-signed message. If you see this text, it means that
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The Internet standard for MIME PGP messages, RFC 2015, was published in 1996.
To open this message correctly you will need to install E-mail or Usenet
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Content-Disposition: inline
Content-Transfer-Encoding: 7bit

cheng.nospam@gmail.com writes:

> Thanks for the reply. I knew that most of the email system should
> support 8bit nowadays, except something like exchange 5.5. When these
> mail servers communicating directly, it should not be a problem because
> the sender and receipient SMTP server talk directly and they could
> negotiate the best encoding methods.
>
> However, when there is a gateway between them, the situation is
> different.

No, it's not. You need to lose this notion completely. A mail server is a
mail server. Something that sends and receives SMTP is no different than
anything else that sends and receives SMTP.

Using SMTP to deliver a message to the recipient's mail server is no
different than using SMTP to deliver a message to a fixed intermediate
relay, which then assumes responsibility to forward the mail to its intended
recipients. In all cases it's the exact same SMTP, and the only difference
is that you connect to a fixed mail server to talk SMTP, instead of looking
up the recipients' DNS records and connecting to the recipients' designated
mail server.

In many case the "destination" mail server you think is, isn't. The
"destination" mail server is also an intermediate server that accept all
mail addressed to an organization, and forwards them internally to the
appropriate mailboxes (which introduces its own sorts of problems, but
that'a different topic).

No matter who you're sending mail to -- the recipients' mail servers, or an
intermediate so-called "firewall", as long as SMTP is involved the sender
always follows the same exact steps and procedures.

> In my case, the mail gateway is Microsoft IIS 6. It
> supports 8-bit MIME in nature. When sending email from my backend to
> other Internet SMTP server, it must send through my mail gateway. The
> mail will be encoded in 8-bit as IIS supports it. However, when this
> 8bit message is directed to the destinated server which support 7-bits
> only, the destination server will report "5.6.1 body type not
> supported...." and close the SMTP conversation. I wonder if this is
> the problem of IIS 6 that it could not convert the 8bitmime to 7-bit
> quoted-printable, and vice versa.

I would question whether the destination server is, in fact, 7-bit only. If
you're assuming that based only on the error message, that's not a safe
assumption. These dinosaurs are extremely rare, and I don't come across one
of them more than once or twice, a year.

You have to connect to the destination's server and issue an EHLO in order
to confirm whether or not the destination server is 7-bit, or not. If the
"destination" server does not list 8BITMIME in its ESMTP capabilities, in
the response to the SMTP EHLO command, your "Microsoft IIS 6" server is
broken, and should be returned for a refund. This is 2006. In this
millenium, all mail servers are fully capable of re-encoding 8-bit mail as
quoted-printable.

If the destination server does list 8BITMIME, then it's still probably an
IIS6 bug, but you need to get the log of the SMTP conversation to confirm
this. The only possible way I could imagine this being the destination's
server bug would be if your IIS6 server was sending "BODY=8bitmime", using
lowercase letters, and the destination server is always expecting uppercase
extension keywords. Seems very unlikely to me.

You have to get the SMTP log if you want to go any further with this.



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Re: To set 8bitmime or not?

Sam writes:

> Replace your broken software with one that works correctly. I have no
> idea what kind of ancient, decrepid dinosaur you are running. All
> modern mail servers support 8bitmime, and will automatically reencode
> mail with 8-bit content to quoted-printable when sending mail to
> external servers that claim not to support 8bitmime.
>
> 8-bit mail can be easily converted to 7-bit quoted-printable, and vice
> versa. This is not rocket science, and ways to do that have been
> known for years. This should not be an issue for any mail server.

Sendmail does 8bit-> quoted-printable or 8bit->base64 conversions
when it announces 8BITMIME support on ESMTP.

But I think that changing content-transfer-encoding of mail is
not very often supported by MTAs. Some MTAs can announce 8BITMIME,
but newer will do conversions.

I guess that these MTAs are majority.

/ Kari Hurtta

Re: To set 8bitmime or not?

> You have to connect to the destination's server and issue an EHLO in order
> to confirm whether or not the destination server is 7-bit, or not. If the
> "destination" server does not list 8BITMIME in its ESMTP capabilities, in
> the response to the SMTP EHLO command, your "Microsoft IIS 6" server is
> broken, and should be returned for a refund. This is 2006. In this
> millenium, all mail servers are fully capable of re-encoding 8-bit mail as
> quoted-printable.

In fact, I did that already. I've sent the SMTP EHLO command to my
IIS6 gateway with 8bitmime enabled, it list 8bitmime by default. I
assume the server could handle 8bitmime correctly.

To conclude, 8bit is the ESMTP standard that was widely adopted. When
I enable 8bitmime on both my mail gateway and backend server, I could
send and receive mail without any problem with other 8bit servers. I
could receive mail from other 7bit-only mail servers successfully.
However, I just couldn't send mail to 7bit-only mail server, they
always telling me with SMTP response "5.6.1 Body type not supportred by
remote host". Do you think it is the problem on my side, or on the
recipient's side?

Re: To set 8bitmime or not?

> Sendmail does 8bit-> quoted-printable or 8bit->base64 conversions
> when it announces 8BITMIME support on ESMTP.

> But I think that changing content-transfer-encoding of mail is
> not very often supported by MTAs. Some MTAs can announce 8BITMIME,
> but newer will do conversions.

> I guess that these MTAs are majority.

Kari, thanks for your information. It answered some of my questions. :)

Re: To set 8bitmime or not?

This is a MIME GnuPG-signed message. If you see this text, it means that
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Content-Transfer-Encoding: 7bit

cheng.nospam@gmail.com writes:

>> You have to connect to the destination's server and issue an EHLO in order
>> to confirm whether or not the destination server is 7-bit, or not. If the
>> "destination" server does not list 8BITMIME in its ESMTP capabilities, in
>> the response to the SMTP EHLO command, your "Microsoft IIS 6" server is
>> broken, and should be returned for a refund. This is 2006. In this
>> millenium, all mail servers are fully capable of re-encoding 8-bit mail as
>> quoted-printable.
>
> In fact, I did that already. I've sent the SMTP EHLO command to my
> IIS6 gateway with 8bitmime enabled, it list 8bitmime by default. I
> assume the server could handle 8bitmime correctly.

I said "the destination server", and not your gateway.

> To conclude, 8bit is the ESMTP standard that was widely adopted. When
> I enable 8bitmime on both my mail gateway and backend server, I could
> send and receive mail without any problem with other 8bit servers. I
> could receive mail from other 7bit-only mail servers successfully.
> However, I just couldn't send mail to 7bit-only mail server, they
> always telling me with SMTP response "5.6.1 Body type not supportred by
> remote host". Do you think it is the problem on my side, or on the
> recipient's side?

As I said in my last message, if I were to place a bet, I would bet that
your IIS server is broken; but you cannot make any definitive conclusions
until you log the SMTP conversation.


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Re: To set 8bitmime or not?

Sam writes:

> cheng.nospam@gmail.com writes:
>
> >> You have to connect to the destination's server and issue an EHLO in order
> >> to confirm whether or not the destination server is 7-bit, or not. If the
> >> "destination" server does not list 8BITMIME in its ESMTP capabilities, in
> >> the response to the SMTP EHLO command, your "Microsoft IIS 6" server is
> >> broken, and should be returned for a refund. This is 2006. In this
> >> millenium, all mail servers are fully capable of re-encoding 8-bit mail as
> >> quoted-printable.
> >
> > In fact, I did that already. I've sent the SMTP EHLO command to my
> > IIS6 gateway with 8bitmime enabled, it list 8bitmime by default. I
> > assume the server could handle 8bitmime correctly.
>
> I said "the destination server", and not your gateway.

I've sent the SMTP EHLO command to destinations server, and it did not
reply 8bitmime. I could confirm the destination server is 7-bit only.
I don't understand why it is the IIS6 problem when the 7-bit only
destination server does not list 8BITMIME in response to my EHLO
command. Could you please elaborate more on this? Thank you!

Re: To set 8bitmime or not?

This is a MIME GnuPG-signed message. If you see this text, it means that
your E-mail or Usenet software does not support MIME signed messages.
The Internet standard for MIME PGP messages, RFC 2015, was published in 1996.
To open this message correctly you will need to install E-mail or Usenet
software that supports modern Internet standards.

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Content-Type: text/plain; format=flowed; charset="US-ASCII"
Content-Disposition: inline
Content-Transfer-Encoding: 7bit

cheng.nospam@gmail.com writes:

> I've sent the SMTP EHLO command to destinations server, and it did not
> reply 8bitmime. I could confirm the destination server is 7-bit only.
> I don't understand why it is the IIS6 problem when the 7-bit only
> destination server does not list 8BITMIME in response to my EHLO
> command. Could you please elaborate more on this? Thank you!

Because this is the year 2006, not 1996. By now, every mail server should
be fully capable of automatically recoding all 8-bit mail into 7-bit
quoted-printable encoding, to deliver mail to some ancient mail server
that's incapable of receiving 8bit mail.

I could understand that, if ten years ago, an 8-bit mail server was not
capable of re-coding 8-bit mail into 7-bit form, in this situation. But by
now, there are many free software libraries out there that simply this task,
and it's no longer an issue. Unlike _YOU_, I, myself can send 8-bit mail to
any 7-bit mail server without any problems, because my mail server will
automatically translate 8-bit mail to 7-bit quoted-printable.

This is something that many free mail servers for Linux and Unix have been
able to do for many YEARS, but, apparently, is too complicated for Microsoft
to properly implement in their bugware.

If you want to send mail to any mail server out there, without giving a damn
whether the message is 7-bit or 8-bit, or whether the remote mail server
supports 8bitmime, you'll just have to reformat your hard drive, and install
Linux. This is not an issue for anyone running Linux.


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Re: To set 8bitmime or not?

cheng.nospam@gmail.com wrote in
news:1143595592.576701.21540@j33g2000cwa.googlegroups.com:

>...
> I've sent the SMTP EHLO command to destinations server, and it
> did not reply 8bitmime. I could confirm the destination server
> is 7-bit only. I don't understand why it is the IIS6 problem
> when the 7-bit only destination server does not list 8BITMIME in
> response to my EHLO command. Could you please elaborate more on
> this? Thank you!

The remote server validly told your server that it does not accept 8-
bit encodings by failing to include 8BITMIME in its EHLO response,
which it is entitled to do. Your server ignored this and sent an 8-
bit encoding anyway. Your server is wrong to do so, it should have
converted the message part to a 7-bit encoding like Quoted-printable.

- Fred

Re: To set 8bitmime or not?

Thanks for your clear explaination. I'll seek a gateway to replace IIS
for handling mail with servers using different encoding method. BTW,
is the translation of 8-bit mail to 7-bit quoted-printable, and vice
versa, defined in any RFC?

Re: To set 8bitmime or not?

Thanks for your kind reply. Do you think it is common for MTA to
convert the message part of a 8-bit mime to a 7-bit encoding like
Quoted-printable?

Re: To set 8bitmime or not?

This is a MIME GnuPG-signed message. If you see this text, it means that
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Content-Disposition: inline
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cheng.nospam@gmail.com writes:

> Thanks for your clear explaination. I'll seek a gateway to replace IIS
> for handling mail with servers using different encoding method. BTW,
> is the translation of 8-bit mail to 7-bit quoted-printable, and vice
> versa, defined in any RFC?

8bit and quoted-printable encodings are defined by RFC 2045.

The translation algorithm is logically derived from both encodings'
definitions.



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Re: To set 8bitmime or not?

This is a MIME GnuPG-signed message. If you see this text, it means that
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The Internet standard for MIME PGP messages, RFC 2015, was published in 1996.
To open this message correctly you will need to install E-mail or Usenet
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Content-Type: text/plain; format=flowed; charset="US-ASCII"
Content-Disposition: inline
Content-Transfer-Encoding: 7bit

cheng.nospam@gmail.com writes:

> Thanks for your kind reply. Do you think it is common for MTA to
> convert the message part of a 8-bit mime to a 7-bit encoding like
> Quoted-printable?

Amongst free software, I can only thing of one MTA in common use that's too
stupid to do it. Fortunately, the MTA in question is slowly fading in
obscurity, and the ones that are left do the conversion, as necessary.


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