Multiple email when using SendMail

  • Thread starter Thread starter Glen Wolinsky
  • Start date Start date
G

Glen Wolinsky

We have written a service that runs in the background to deliver email
to our users. The emails are generated from data in SQL that our
application creates. This service sends out thousands of emails
everyday with little or not problem. The code works!

However, we are experiencing an interesting problem. During the
night, we send out reminder emails that have been generated in the
database by overnight processes. This usually amounts to several
hundred or even thousands being delivered in one relatively quick
burst!

This scenario seems to cause the server to send some of the emails
multiple times. Our firewall monitors show the server sending these
multiples but the database (updated by the service) shows an email
only being processed once!

We've checked and re-checked our code (it's pretty simple code,
overall). If the code was sending multiple times, we "should" see
multiple instances in the database (it records the sending of each
individual email immdiately after the sendmail command).

Has anyone else seen this problem before?

Any help would be greatly appreciated.

Sincerely,
Glen Wolinsky
 
You may want to consider posting to another group, perhaps a sendmail group
(Though I highly doubt it is a sendmail issue), or a group dedicated to the
language of the code you are using. And be prepared to post code, I don't
see much anyone can do to help you without seeing at least that.

--Michael
 
Hi Glen,


Thanks for posting in the community! My name is Steven, and I'll be
assisting you on this issue.
From your description, you used some code to send email in your back ground
service. You found that when during night, the sending task is of high
volum, many mail will be found delivered several times though they were
checked
only sent once in the database, yes?
If there is anything I misunderstood, please feel free to let me know.

As you mentioned that
"Our firewall monitors show the server sending these
multiples but the database (updated by the service) shows an email
only being processed once!"
I think the problem is likely due to something incorrect with the mail
server. Sometimes, when the volum of the mail server's task is too high,
there may occur some errors which cause the failure of sending a certain
mail. Also, do you think it possible that the mail server will try
resending a mail when it fail to send it the first time? Because in the
mail server(IIS smtp server) , we can configure the server to attempt
sending again when the former attempts fail, so I think this is also a
potential cause of the problem.
If you need more detailed infos on mailserver(do you use the MS' mailserver
or other?), you may try post a request in IIS group for help.

Please check out the preceding suggestions. If you have any question,
please feel free to let me know.


Regards,

Steven Cheng
Microsoft Online Support

Get Secure! www.microsoft.com/security
(This posting is provided "AS IS", with no warranties, and confers no
rights.)
 
Hi Glen,


Have you had a chance to check out my suggestion or have you found the root
cause of the problem? If you have any new findings or need any further
help, please feel free to post here.


Regards,

Steven Cheng
Microsoft Online Support

Get Secure! www.microsoft.com/security
(This posting is provided "AS IS", with no warranties, and confers no
rights.)
 
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