George Jebaraj - Zimbra mail server

Question

Hi AWS Team,
I have setup zimbra mail server in AWS EC2 instance.
Seems some ports are blocking. Note I have opened all ports in AWS security group temporarily(open All Traffic allowed to 0.0.0.0/0)

Mail server domain name : webmail.mtsdesignhub.com
Mail server domain name : mtsdesignhub.com
Public static IP : 13.200.170.253
telnet 13.200.170.253 22  - respond
telnet 13.200.170.253 25  - Not respond

My request is kindly open below ports as soon as possiable.
25,80,110,143,443,465,587,993,995,5222,5223,9071,7071,7025

SMTP	25	tcp	Public
HTTP	80	tcp	Public
POP3	110	tcp	Public
IMAP	143	tcp	Public
LDAP	389	tcp	Public
HTTPS	443	tcp	Public
SMTPS	465	tcp	Public
SMTP Submission	587	tcp	Public
IMAPS	993	tcp	Public
POP3S	995	tcp	Public
(Admin Interface)	7071	tcp	Public
SOAP Auth	7073	tcp	Public
LMTP	7025	tcp	Public

Thanks and regards
George 
+91 9940558509

Riku_Kobayashi · Answer

Hello.

AWS blocks port 25, so communication is not possible even if it is allowed in the security group.  
To be able to communicate, you need to remove the restriction by following the steps described in the document below.  
https://repost.aws/knowledge-center/ec2-port-25-throttle

By the way, I have seen that even if you send a request, the request may not be allowed depending on the use case, so please be careful.  
In some cases, it may be better to use Amazon SES or set up your email to be sent using an SMTP port other than port 25.

George Jebaraj - Zimbra mail server

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