"Samir Patel" <SamirPa***@discussions.microsoft.com> wrote in message
news:F961EE5C-8CD2-4221-8061-2CC1F487055E@microsoft.com...
> Hi,
>
> I have a client running SBS 2003 R2 Standard, their email domain is (let's
> say) company.co.uk
>
> A particular external sender often sends email addressed to multiple users
> @company.co.uk
>
> Each of the recipients (for example 2) receives the same number of
> messages
> in their mailbox - 2 recipients, 2 copies each. 6 recipients, 6 copies
> each
>
> The company.co.uk email is hosted at an external ISP, and email is
> downloaded using a POP3 client called POPBeamer. POPBeamer then sends
> emails
> to Exchange by SMTP
>
> What happens is:
>
> - sender sends email addressed to 2 people @ company.co.uk
> - company.co.uk's ISP's POP3 mailbox holds 2 emails, each with different
> Message IDs
> - POPBeamer downloads the first email, looks at the Message ID, decides it
> hasn't seen it before and sends the email to Exchange. Exchange delivers
> the
> email to all the company.co.uk recipients listed (2)
> - POPBeamer downloads the second email, looks at the Message ID, decides
> it
> hasn't seen it before and sends the email to Exchange. Exchange delivers
> the
> email to all the company.co.uk recipients listed (2)
> - Each person now has 2 copies of the email
>
> This is happening with 2 or 3 different senders (from different companies,
> some in the UK, some in China)
>
> With all other senders, the 2 emails that are received by the ISP and
> stored
> in their mailbox for download by POPBeamer have the same Message ID. This
> happens:
>
> - sender sends email addressed to 2 people @ company.co.uk
> - company.co.uk's ISP's POP3 mailbox holds 2 emails, each with different
> Message IDs
> - POPBeamer downloads the first email, looks at the Message ID, decides it
> hasn't seen it before and sends the email to Exchange. Exchange delivers
> the
> email to all the company.co.uk recipients listed (2)
> - POPBeamer downloads the second email, looks at the Message ID, decides
> it
> *has* seen it before (in the previous 2 hours which is how long it
> remembers
> IDs for) ditches it
> - Each person now has *1* copy of the email
>
> My client is on my back as they are getting their mailboxes clogged with
> duplicate copies of these emails (the emails from their Chinese contact
> typically have large attachments)
>
> As far as I can tell, there is no way round this, because the Exchange
> looks
> for duplicates based on both the Message ID and the client submit time
> (like
> it says here http://msexchangeteam.com/archive/2004/07/14/183132.aspx ),
> and
> POPBeamer does it solely on the Message ID
> (http://www.dataenter.co.at/doc/popbeamer_admin_options.htm , look for the
> section titled "Ignoring message with duplicate message ID").
>
> The POPBeamer site talks about the ISP storing multiple copies in the
> mailbox, but I imagine even if the ISP were to do duplicate detection, it
> would be done using the Message ID
>
> Does anyone else know a way of fixing this problem at our end, short of
> getting the external senders to change their email systems?

"Ed Crowley [MVP]" wrote:

> POP3 is a single mailbox client mail retrieval protocol, not a mail
> transport protocol. Any attempt to use it as a mail transport protocol is a
> great big kludge. Exchange is designed to connect to the Internet using
> SMTP.
>
> http://www.swinc.com/resource/exch_smtp_diatribe.htm
>
> http://www.swinc.com/resource/exch_dq.htm
>
> http://www.swinc.com/resource/exch_smtp.htm
>
> That said, I don't understand why someone would use a third-party kludgy
> POP3 connector when SBS bundles a kludgy POP3 connector all its own.  In
> other words, this is a double kludge.
>
> In all seriousness, what you're seeing is not at all atypical of the kinds
> of problems people see with this great big kludge.
>
> --
> Ed Crowley
> MVP - Exchange
> "Protecting the world from PSTs and brick backups!"
>
>
> "Samir Patel" <SamirPa***@discussions.microsoft.com> wrote in message
> news:F961EE5C-8CD2-4221-8061-2CC1F487055E@microsoft.com...
> > Hi,
> >
> > I have a client running SBS 2003 R2 Standard, their email domain is (let's
> > say) company.co.uk
> >
> > A particular external sender often sends email addressed to multiple users
> > @company.co.uk
> >
> > Each of the recipients (for example 2) receives the same number of
> > messages
> > in their mailbox - 2 recipients, 2 copies each. 6 recipients, 6 copies
> > each
> >
> > The company.co.uk email is hosted at an external ISP, and email is
> > downloaded using a POP3 client called POPBeamer. POPBeamer then sends
> > emails
> > to Exchange by SMTP
> >
> > What happens is:
> >
> > - sender sends email addressed to 2 people @ company.co.uk
> > - company.co.uk's ISP's POP3 mailbox holds 2 emails, each with different
> > Message IDs
> > - POPBeamer downloads the first email, looks at the Message ID, decides it
> > hasn't seen it before and sends the email to Exchange. Exchange delivers
> > the
> > email to all the company.co.uk recipients listed (2)
> > - POPBeamer downloads the second email, looks at the Message ID, decides
> > it
> > hasn't seen it before and sends the email to Exchange. Exchange delivers
> > the
> > email to all the company.co.uk recipients listed (2)
> > - Each person now has 2 copies of the email
> >
> > This is happening with 2 or 3 different senders (from different companies,
> > some in the UK, some in China)
> >
> > With all other senders, the 2 emails that are received by the ISP and
> > stored
> > in their mailbox for download by POPBeamer have the same Message ID. This
> > happens:
> >
> > - sender sends email addressed to 2 people @ company.co.uk
> > - company.co.uk's ISP's POP3 mailbox holds 2 emails, each with different
> > Message IDs
> > - POPBeamer downloads the first email, looks at the Message ID, decides it
> > hasn't seen it before and sends the email to Exchange. Exchange delivers
> > the
> > email to all the company.co.uk recipients listed (2)
> > - POPBeamer downloads the second email, looks at the Message ID, decides
> > it
> > *has* seen it before (in the previous 2 hours which is how long it
> > remembers
> > IDs for) ditches it
> > - Each person now has *1* copy of the email
> >
> > My client is on my back as they are getting their mailboxes clogged with
> > duplicate copies of these emails (the emails from their Chinese contact
> > typically have large attachments)
> >
> > As far as I can tell, there is no way round this, because the Exchange
> > looks
> > for duplicates based on both the Message ID and the client submit time
> > (like
> > it says here http://msexchangeteam.com/archive/2004/07/14/183132.aspx ),
> > and
> > POPBeamer does it solely on the Message ID
> > (http://www.dataenter.co.at/doc/popbeamer_admin_options.htm , look for the
> > section titled "Ignoring message with duplicate message ID").
> >
> > The POPBeamer site talks about the ISP storing multiple copies in the
> > mailbox, but I imagine even if the ISP were to do duplicate detection, it
> > would be done using the Message ID
> >
> > Does anyone else know a way of fixing this problem at our end, short of
> > getting the external senders to change their email systems?
>
>
>

"Samir Patel" <SamirPa***@discussions.microsoft.com> wrote in message
news:8B3867F4-D6C5-4FB5-A0E9-CF540F8A1EE8@microsoft.com...
> Thanks Ed.
>
> I don't think that POP3 is the issue here. Please correct me if I am
> wrong,
> I often am.
>
> The reason we use this particular 3rd party tool is because it allows us
> to
> connect more often than every 15 minutes (the MS POP3 connector's limit),
> and
> allows to leave email on the POP3 server for a specified number of days
> (MS
> POP3 connector doesn't).
>
> The reason we use POP3 is because the client has an ADSL connection, and
> if
> this were to go down (as ADSL connections are prone to do), we do not want
> people sending emails to their domain to start getting delay
> notifications.
> Their email provider does not offer an SMTP "store & forward" / ETRN
> service.
> We are more than happy to switch email providers if SMTP delivery will fix
> the problem. What I don't want to do is make the switch and find there is
> no
> change.
>
> We have (probably) a couple of dozen different networks we manage which
> either use the MS POP3 connector or others (GFI Mail to Exchange or
> POPBeamer). The only problem we ever have is this duplication (at only 2
> sites). But yes, we are working on getting them all switched to SMTP
> delivery.
>
> The POP3 connector software we use (POPBeamer) sends the emails to
> Exchange
> using SMTP.
>
> POPBeamer and Exchange both use Message IDs for duplication detection
> (Exchange uses submission times as well).
>
> If I look at the SMTP headers of an email that I received 3 times, each
> set
> of headers show different Message IDs, all the way through as the email
> passes through various SMTP servers on the Internet.
>
> The duplication only happens when emails are sent from one or two sender
> domains. All other domains who send email to company.co.uk are fine: an
> email
> sent to 3 people @company.co.uk, each person gets 1 copy.
>
> Will switching to SMTP (either "store & forward" or direct by setting the
> MX
> record to the company's external IP address) solve this problem, in view
> of
> the fact that there are differing Message IDs in mail from these senders?
> I'm
> not sure it will.
>
> If switching to SMTP delivery will fix the problem, then we will happily
> make the change, but what I don't want to do is get the change made, which
> will involve either taking chances with an ADSL connection or switching to
> a
> "store & forward provider" and find there is no change.
>
> The senders from whom we are receiving multiple copies of these emails say
> we are the only people who are reporting this problem. Of course this
> could
> mean that other domains are just not telling them, but then it could be a
> POP3 problem.
>
> Sorry if I've rambled a bit here, I'm trying to mount a defence of my
> using
> POP3 as well as get enough info to you to help.
>
> Thanks in advance.
>
> Samir
>
> "Ed Crowley [MVP]" wrote:
>
>> POP3 is a single mailbox client mail retrieval protocol, not a mail
>> transport protocol. Any attempt to use it as a mail transport protocol is
>> a
>> great big kludge. Exchange is designed to connect to the Internet using
>> SMTP.
>>
>> http://www.swinc.com/resource/exch_smtp_diatribe.htm
>>
>> http://www.swinc.com/resource/exch_dq.htm
>>
>> http://www.swinc.com/resource/exch_smtp.htm
>>
>> That said, I don't understand why someone would use a third-party kludgy
>> POP3 connector when SBS bundles a kludgy POP3 connector all its own.  In
>> other words, this is a double kludge.
>>
>> In all seriousness, what you're seeing is not at all atypical of the
>> kinds
>> of problems people see with this great big kludge.
>>
>> --
>> Ed Crowley
>> MVP - Exchange
>> "Protecting the world from PSTs and brick backups!"
>>
>>
>> "Samir Patel" <SamirPa***@discussions.microsoft.com> wrote in message
>> news:F961EE5C-8CD2-4221-8061-2CC1F487055E@microsoft.com...
>> > Hi,
>> >
>> > I have a client running SBS 2003 R2 Standard, their email domain is
>> > (let's
>> > say) company.co.uk
>> >
>> > A particular external sender often sends email addressed to multiple
>> > users
>> > @company.co.uk
>> >
>> > Each of the recipients (for example 2) receives the same number of
>> > messages
>> > in their mailbox - 2 recipients, 2 copies each. 6 recipients, 6 copies
>> > each
>> >
>> > The company.co.uk email is hosted at an external ISP, and email is
>> > downloaded using a POP3 client called POPBeamer. POPBeamer then sends
>> > emails
>> > to Exchange by SMTP
>> >
>> > What happens is:
>> >
>> > - sender sends email addressed to 2 people @ company.co.uk
>> > - company.co.uk's ISP's POP3 mailbox holds 2 emails, each with
>> > different
>> > Message IDs
>> > - POPBeamer downloads the first email, looks at the Message ID, decides
>> > it
>> > hasn't seen it before and sends the email to Exchange. Exchange
>> > delivers
>> > the
>> > email to all the company.co.uk recipients listed (2)
>> > - POPBeamer downloads the second email, looks at the Message ID,
>> > decides
>> > it
>> > hasn't seen it before and sends the email to Exchange. Exchange
>> > delivers
>> > the
>> > email to all the company.co.uk recipients listed (2)
>> > - Each person now has 2 copies of the email
>> >
>> > This is happening with 2 or 3 different senders (from different
>> > companies,
>> > some in the UK, some in China)
>> >
>> > With all other senders, the 2 emails that are received by the ISP and
>> > stored
>> > in their mailbox for download by POPBeamer have the same Message ID.
>> > This
>> > happens:
>> >
>> > - sender sends email addressed to 2 people @ company.co.uk
>> > - company.co.uk's ISP's POP3 mailbox holds 2 emails, each with
>> > different
>> > Message IDs
>> > - POPBeamer downloads the first email, looks at the Message ID, decides
>> > it
>> > hasn't seen it before and sends the email to Exchange. Exchange
>> > delivers
>> > the
>> > email to all the company.co.uk recipients listed (2)
>> > - POPBeamer downloads the second email, looks at the Message ID,
>> > decides
>> > it
>> > *has* seen it before (in the previous 2 hours which is how long it
>> > remembers
>> > IDs for) ditches it
>> > - Each person now has *1* copy of the email
>> >
>> > My client is on my back as they are getting their mailboxes clogged
>> > with
>> > duplicate copies of these emails (the emails from their Chinese contact
>> > typically have large attachments)
>> >
>> > As far as I can tell, there is no way round this, because the Exchange
>> > looks
>> > for duplicates based on both the Message ID and the client submit time
>> > (like
>> > it says here
>> > http://msexchangeteam.com/archive/2004/07/14/183132.aspx ),
>> > and
>> > POPBeamer does it solely on the Message ID
>> > (http://www.dataenter.co.at/doc/popbeamer_admin_options.htm , look for
>> > the
>> > section titled "Ignoring message with duplicate message ID").
>> >
>> > The POPBeamer site talks about the ISP storing multiple copies in the
>> > mailbox, but I imagine even if the ISP were to do duplicate detection,
>> > it
>> > would be done using the Message ID
>> >
>> > Does anyone else know a way of fixing this problem at our end, short of
>> > getting the external senders to change their email systems?
>>
>>
>>