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<div class="moz-cite-prefix">On 8/2/23 05:08, Dr. Rolf Jansen wrote:<br>
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<pre class="moz-quote-pre" wrap="">Am 07.02.2023 um 17:54 schrieb jeremy ardley <a class="moz-txt-link-rfc2396E" href="mailto:jeremy@ardley.org"><jeremy@ardley.org></a>:
On 7/2/23 22:01, Dr. Rolf Jansen wrote:
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<pre class="moz-quote-pre" wrap="">To begin with, usage of Amazons Simple Email Service (SES) is mandatory for outgoing mails from AWS-EC2 instances.
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I run AWS-EC2 instances using postfix to send a receive mail. They can send direct assuming I set up suitable SPF, but they typically forward mail to another host under my control that is not on AWS to use as the outgoing server.
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OK, that’s another use case. Many do use a full fledged Postfix/Dovecot installation. However the outgoing port 25 into the internet is blocked by AWS, and therefore we may either use a third party relay for our outgoing emails or may use SES, which is not that bad - except some unusual peculiarities.
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<div class="moz-signature">This is off topic, but to be precise:</div>
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<div class="moz-signature">- AWS throttles but does not block
traffic to a *destination* port 25.</div>
<div class="moz-signature">- The *origin* port on the EC2 instance
is an unprivilged port, not port 25<br>
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<div class="moz-signature">- If you use a relayhost you typically
send from an unprivilged EC2 port to port 587 on the relay host</div>
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<font size="4" color="DarkSlateGray">Jeremy</font></div>
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