T wrote:

On 02/13/2018 01:19 AM, T wrote:
Hi All,

I got a call from a customer that whenever her boss sends out
and eMail with an attachment from Outlook (version unknown),
that the eMail will send out up to 20 times.* With no
attachment, only once.

He is on Pop3 without mail being held on the server.
(I turned it off a month ago.)

I am thinking it is an issue with his eMail provider.

Have you seen this before?* Any word of wisdom?

Many thanks,
-T

Follow up:

Hi All,

Boy what a difference it makes to be "on site".

Well, it wasn't "all" eMails with attachments, it was particular
eMails with attachments. This time the user the duplicates
showed up on did not delete them, so I could look at them

1) the offending eMail never showed up in the sender's sent box
(others did).

2) the attachments with the issue had one thing in common:
they were large 10 MB to 18 MB.

On troubleshooting, I found that someone had put his Outlook's
"Schedule and automatic send/receive every" to 3 minutes.

A 18 MB attachment takes 25 minutes to send. (His Internet
needs an upgrade, which is my next call after I finish writing
this.) And every three minutes it would start over and resend
the guy.

I set it back to the default of 30 minutes.

There is an excellent reference describing this problem, with
full paths and all to setting over at

Outlook sends duplicate emails:
https://social.technet.microsoft.com...?forum=outlook

Thank you all for the tips and moral support!

-T

Ah, the "overly short polling interval" problem. I consider 5 minutes
to be the shortest that should be used. Shorter intervals are rude to
the e-mail provider since the user is consuming the provider's resources
for no real benefit. Users rarely get more than a few e-mails every 5
minutes and often much less than that. Even if there were tons of
incoming e-mails that were continuously rolling in, it would take more
than 5 minutes to go through a dozen of them at a time. E-mail is not a
chat venue; i.e., immediacy is not a behavior expected of e-mail versus
using a chat room or texting.

I never attach large files to my e-mails. That is rude to the
recipient. They may not want the large attachment, they don't want
senders wasting their bandwidth to get huge e-mails, they don't want to
wait for the large file transfer (e-mail is NOT a file transfer
protocol, especially since there is no resume or CRC), recipient's would
prefer to have a choice of if and when they retrieve a huge e-mails, and
sending huge e-mails could render a recipient's account dead in that
their disk quota got consumed and no further e-mails can be accepted
into their account until they clean it out. While Outlook can be
configured with a threshold of how large is too large to download, most
users never employ that option. Hell, most never visit the send/receive
settings.

It is not only when sending huge e-mails that an overly short poll
interval is inappropriate. It is also when receiving e-mails. If
someone, just like this rude user, sent them a huge e-mails, the
recipient's client would be in the middle of receiving a huge e-mail but
their client aborts that receive operation because another one started.
The user asks why they cannot receive any e-mails they notice are
available when using the webmail client to their account. That's
because they don't give their e-mail client a chance to finish a mail
poll that has a huge e-mail getting downloaded before they start yet
another mail poll that interrupts the prior one.

The overly short polling interval is a problem only with POP (and, as
you've seen, with SMTP). The slower the bandwidth then the longer the
polling interval should be. Figure how long it takes to upload a 100MB
file (since downloads are usually much shorter due to asynchronous
downstream versus upstream speeds). That would be the minimum polling
interval. Even with a high-speed connection, also remember that overly
short polling intervals are rude to the e-mail provider because you
don't get that e-mails to qualify for such a short poll interval and
even if you did then you couldn't read all those e-mails within that
overly short poll interval.

With IMAP and PUSH support, there is no polling. I suspect most IMAP
providers support PUSH. That has the server push a new message to your
client when it becomes available at the server. So you will get your
e-mails soon after they arrive without having to poll for them. There
are lots of other advantage to IMAP over POP but I won't go into them
now. SMTP can still suffer the overly short poll interval problem in
that the client is interrupting a current mail session to start another
one. E-mail is *NOT* a chat client nor does it substitute for FTP.

To stop being rude to recipients, the sender should upload the huge file
to some online storage service. OneDrive and Google Drive are free as
well as many other file services. Upload the huge file, put a URL to it
in the e-mail, keep the e-mail small, and give the choice to the
recipient if they want to retrieve the file. Stop shoving it down their
throat just because you, the sender, think it's an important file. A
friend might offer me a drink but I would not appreciate them shoving it
into my hands whether I wanted it or not.