Setting Up Mail Server Operation for CentOS Web Panel Web Hosting Control Panel on Amazon AWS Cloud
From: Turritopsis Dohrnii Teo En Ming
Date: Tue Feb 25 2020 - 09:06:22 EST
Subject: Setting Up Mail Server Operation for CentOS Web Panel Web
Hosting Control Panel on Amazon AWS Cloud
Author: Mr. Turritopsis Dohrnii Teo En Ming, Singapore
Date: 25 Feb 2020 Tuesday
Before embarking on this guide, you should read the following guide
Guide: Mr. Teo En Ming's Guide to Deploying CentOS Web Panel (CWP) Web
Hosting Control Panel on Amazon AWS Cloud
Redundant blog links:
EXTREMELY DETAILED INSTRUCTIONS OF TEO EN MING'S GUIDE
Teo En Ming's DNS Zone File for domain teo-en-ming.com on Primary DNS
@ IN SOA ns1.teo-en-ming.com. ceo.teo-en-ming.com. (
2020022502 ; Serial
604800 ; Refresh
86400 ; Retry
2419200 ; Expire
604800 ) ; Negative Cache TTL
; name servers - NS records
IN NS ns1.teo-en-ming.com.
IN NS ns2.teo-en-ming.com.
; mail servers - MX records
IN MX 0 mail.teo-en-ming.com.
; name servers - A records
ns1.teo-en-ming.com. IN A 184.108.40.206
ns2.teo-en-ming.com. IN A 220.127.116.11
; mail servers - A records
mail.teo-en-ming.com. IN A 18.104.22.168
; Additional A records
www.teo-en-ming.com. IN A 22.214.171.124
teo-en-ming.com. IN A 126.96.36.199
; Sender Policy Framework (SPF) TXT records
teo-en-ming.com. IN TXT "v=spf1 ip4:188.8.131.52 -all"
Guide: Mail Exchange Record (MX)
Guide: How To: Lowering Your DNS TTLs
Discussion: Postfix: âConnection timed outâ on all outbound email
"For anyone who found this question but is on AWS EC2: outgoing SMTP
intentionally rate limited, but you can ask to have it relaxed."
Discussion: Intermittent exim gmail smtp connection timeout
"Just an update for anyone with a similar issue - with some fresh eyes
and some more googling it sounds like this may be caused by some SMTP
rate limitations built into the AWS EC2 network as Spam prevention.
They have a form to register to remove outgoing smtp connection
I've submitted and will update if this resolves the issues I was
"Amazon SMTP traffic management indeed seems to have been the cause.
Within a couple of hours of filling out the above form, I got an email
confirmation from AWS that "traffic restrictions had been removed" and
normal function resumed immediately.
Confusing the matters is that this SMTP traffic management is not
documented well (and sometimes with contradicting information). It does
not appear to be a hard cap limit, nor does it trigger any notification
when it's applied - it actually appears to be a *throttle* on common
SMTP ports, triggered by a very small number of connections, beyond
which it allows a certain number of connections per/hour - which would
absolutely create the kind of "intermittent" connectivity issues I saw
(and the odd delivery order of mail in the queue depending on when a
retry "won the lottery" to negotiate a connection).
Anyway - I hope that info is of some use to others in the future!"
Guide: Installing Telnet In CentOS/RHEL/Scientific Linux 6 & 7
Amazon Web Services' Reply to Teo En Ming
We approved your request for the removal of the EC2 email sending
limitations on your Amazon Web Services account! If you requested
removal of email sending limits on any other Amazon Elastic IPs, they've
also been removed.
Because reverse DNS record entries are commonly considered in anti-spam
filters, we recommend assigning a reverse DNS record to the Elastic IP
address you use to send email to third parties. Please use the form
located at this link to request a reverse DNS entry:
If you'd like to proceed with assigning a reverse DNS record to the
Elastic IP, the first step would be to configure the A record for the
domain to match the desired PTR record on your side.
Please follow the instructions at the link below to create the A record:
Please let us know if you have any questions.
Amazon Web Services
Guide: How to create an SPF TXT record?
Guide: Linux BIND DNS Configure Sender Policy Framework ( SPF ) an
e-mail Anti Forgery System
Creating New User Account in CentOS Web Panel
Login to CentOS Web Panel Admin Panel.
From the left menu, click on User Accounts, then select New Account.
Domain name: teo-en-ming.com
Reseller: Not checked
Process limit: 40
Open files: 150
Backup user account: checked
Shell Access: Disabled by default for security reasons: Unchecked
AutoSSL: Domain must be pointed to the server: Unchecked
Setting Up New Email Account
Login to CentOS Web Panel User Panel.
From the left menu, click Email Accounts, then click Email Accounts.
Click Add a New MailBox.
Email Address: ceo@xxxxxxxxxxxxxxx
Quota MB: 16000
Using Your New Email Account
Login to Roundcube Webmail.
From the left menu, click Identities, then click ceo@xxxxxxxxxxxxxxx
Display Name: Turritopsis Dohrnii Teo En Ming
Congratulations! You can now start using your new email account.
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The Gospel for all Targeted Individuals (TIs):
[The New York Times] Microwave Weapons Are Prime Suspect in Ills of
U.S. Embassy Workers
Singaporean Mr. Turritopsis Dohrnii Teo En Ming's Academic
Qualifications as at 14 Feb 2019 and refugee seeking attempts at the
United Nations Refugee Agency Bangkok (21 Mar 2017), in Taiwan (5 Aug
2019) and Australia (25 Dec 2019 to 9 Jan 2020):
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