Outgoing emails issue


I have deployed Zammad for Help desk services with host name (http://zoho-desk.blueeast.com/).

I was trying to configure Email accounts for inbound and outbound and was successfully configured the imap, and smtp settings.

Inbound is working fine i,e i can see the tickets generated by the customers At zammad dashboard.

The issue I Am facing is that Outbound is not working. On replying a ticket from zammad, customers are unable to receive reply against their tickets.

I have tested it with my testing email accounts and I am unable to receive replies against my tickets created at ZAMMAD.

My SMTP server is configured properly as I am using the same server for ZOHO Desk application for sending and receiving emails.

I have also tested the SMTP settings of gmail to test the things but issue is same, inbound is working but outbound is not.

*** This is Zammad version 4.1.x**
*** Used Zammad installation type: ( package)**
*** Operating system: Linux (ubuntu :20.04)**
*** Browser + version: Google chrome +** Version 90.0.4430.212 (Official Build) (64-bit)

### Expected behavior:

  • I must be able to reply a ticket from ZAMMAD and customer must get reply email at email address.

### Actual behavior:

  • Customers are unable to receive replies against their tickets.

### Steps to reproduce the behavior:

  • Send test email as customer.

  • Email received at ZAMMAD dashboard as ticket.

  • Reply the Ticket.(No error message shown but customers are unable to receive replies.

Any help would be appreciated.