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We have an enterprise-grade SMTP solution and GBit/s LAN between the Server which is generating the e-Mails and our SMTP server. Of course, it heavily depends on the performance of your SMTP server - and the connection between your sending client and the SMTP server. In my case, the mails are HTML-formatted mails with each 4 images in them and each of the mails has to be generated individually. If I let 2 instances of the script run on the same server (with different e-mail address lists of course) I get on the 1st one about 350.400 mails / min and on the 2nd one about 500.550 mails / min.
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In 2021, I get about 580.620 Mails / Minute through, when using the from within Powershell core.
#Fast email sender server down code
If the mail sent did not succeed, the client code is not affected.The client code sending the mail never has to wait for the actual mail to be sent, which can take a fair while depending on connection speed, latency etc.This approach I think is much superior, simply because: eml files created and deliver them to the recipients or to another SMTP server. Here you can either use the IIS SMTP server or simply make another background thread/process to consume the. What this does is, instead of sending the mail messages over the network, it will write them to the specified folder as standard mime messages (.eml format). What I do in my application is that SmtpClient delivers mails to a folder, by using smtpClient.DeliveryMethod = SmtpDeliveryMethod.SpecifiedPickupDirectory and setting the PickupDirectoryLocation to the wanted directory. However this might not be an issue for you if you change the architecture slightly. Depending on SMTP server and mail size, it is possible to achieve something like at least 50mails/second. There are commercial SMTP components that do and offer much higher performance. Opening a new connection is expensive, and that is probably what takes time.
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NET 4.0, see the differences in documentation for SmtpClient). The SmtpClient class I believe does not reuse the same connection for each mail sent (edit: apparently this is now possible in.