[OFF TOPIC] Re: Pigeonhole Sieve Vacation Reply-To peculiarity with inbound AWS-SES

Michael Peddemors michael at linuxmagic.com
Tue Feb 7 22:49:16 UTC 2023

On 2023-02-07 13:33, jeremy ardley wrote:
> On 8/2/23 05:08, Dr. Rolf Jansen wrote:
>>> Am 07.02.2023 um 17:54 schrieb jeremy ardley<jeremy at ardley.org>:
>>> On 7/2/23 22:01, Dr. Rolf Jansen wrote:
>>>> To begin with, usage of Amazons Simple Email Service (SES) is mandatory for outgoing mails from AWS-EC2 instances.
>>> 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.
>> 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.
> This is off topic, but to be precise:
> - AWS throttles but does not block traffic to a *destination* port 25.
> - The *origin* port on the EC2 instance is an unprivilged port, not port 25
> - If you use a relayhost you typically send from an unprivilged EC2 port 
> to port 587 on the relay host
> Jeremy

And if you DO intend to send out to port 25, remember to update the PTR 
on your EC2 instance.

"Catch the Magic of Linux..."
Michael Peddemors, President/CEO LinuxMagic Inc.
Visit us at http://www.linuxmagic.com @linuxmagic
A Wizard IT Company - For More Info http://www.wizard.ca
"LinuxMagic" a Registered TradeMark of Wizard Tower TechnoServices Ltd.
604-682-0300 Beautiful British Columbia, Canada

This email and any electronic data contained are confidential and intended
solely for the use of the individual or entity to which they are addressed.
Please note that any views or opinions presented in this email are solely
those of the author and are not intended to represent those of the company.

More information about the dovecot mailing list