smtp zimbra connection timeout?

Question

MAIL_DRIVER="smtp"
MAIL_HOST="mail.xxx-xxx.com"
MAIL_PORT="465"
MAIL_USERNAME ="xxx.xxx@xxx-xxx.com"
MAIL_PASSWORD ="******"
MAIL_ENCRYPTION=tls
MAIL_FROM_ADDRESS="xxx.xxx@xxx-xxx.com"
MAIL_FROM_NAME="xxx"

Server Ubuntu

Laravel 5.6

Php 7.1.2

Mail server Zimbra Collaboration

Issue:

success when using smtp google but RTO with smtp zimbra collaboration

Answer 1

Is port 25 already opened?

Answer 2

you must make sure the service is working properly by follow the below instruction :

1. Check host and port by telnel
2. Makesure zimbra can send the email from server (need sysadmin help)
3. Makesure the server IP was listed in whitelist IP
4. Check send the email limit (bandwidth) for zimbra server

Thank you,