Good day,
The Mail App is not working on my server. It used to work and i did not change any settings. Now if i try to add an email account, it logs in but it will say Could Not Open Inbox.
Please anyone help
Please check your logs, like data/nextcloud.log
Sorry Chris. I have checked and I dont know where to start. Sorry man.
No worries 
The Nextcloud mail app offers an extensive logging system to make it easier identifying and tracking down bugs. Please enable debug mode and set the log level to debug in your admin settings. Then, try to reproduce your issue and take another look at data/nextcloud.log and data/horde_imap.log.
Error: PHP Module ‘xxx’ already loaded at Unknown#0]
I am seeing the above error, what should i do?
You have to fix your php config. See the manual of your distribution. One of the modules is included twice.