I have a postfix server hosted at 192.168.187.15 and relay is on 192.168.187.17 . I hosted an php codeignitor email sending application with bulk recipients at 192.168.187.16. i connect the postfix with smtp port 25 from 192.168.187.16 to 192.168.187.15. When sending outbound email with bulk recipeints i got Below error.
220 mail.mycompany.org ESMTP Postfix
hello: 250-mail.mycompany.org
250-PIPELINING
250-SIZE 22020096
250-ETRN
250-AUTH PLAIN LOGIN
250-AUTH=PLAIN LOGIN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
from: 250 2.1.0 Ok
to: 250 2.1.5 Ok
to: 250 2.1.5 Ok
to: 250 2.1.5 Ok
to: 250 2.1.5 Ok
to: 250 2.1.5 Ok
to: 250 2.1.5 Ok
to: 250 2.1.5 Ok
to: 250 2.1.5 Ok
to: 250 2.1.5 Ok
to: 250 2.1.5 Ok
to: 250 2.1.5 Ok
to: 250 2.1.5 Ok
to: 250 2.1.5 Ok
to: 250 2.1.5 Ok
to: 250 2.1.5 Ok
to:
The following SMTP error was encountered:
quit: 250 2.1.5 Ok
The following SMTP error was encountered: 250 2.1.5 Ok Unable to send email using PHP SMTP. Your server might not be configured to send mail using this method
But when i host this application to 192.168.187.16 it does not give any error.
What will be the postfix configuration to send outbound emails with bulk recipients.
For bulk mailing from php or codeignitor application that connected to smtp server I finally found that two configuration must be change or edit in the server that runs the php application.
For Apache:
Open the Apache configuration file /etc/httpd/conf/httpd.conf
add the below line at the end of the or increase as per your requirement.
Timeout 300
ProxyTimeout 300
After that restart the apache server.
sudo systemctl restart httpd
Increase PHP Timeout Settings in /etc/php.ini file.
max_execution_time = 300 # Increase or Update as per requirement in seconds