@SCoccia
Hi,
I'm understanding that your system was working well creating ticket from email and now is not working anymore.
Is the website URL correct in the config/packages/uvdesk.yaml?
What do you have as website URL? You need have the address without https or http.
You can also try to clear cache with the php command php bin/console c:c
Do you get some errors if you run the code to clear cache?
@SCoccia the configuration for your domain doesn't depend by us but it depends on DNS configuration of your domain for the hostname than port and SSL depends on your server configuration.
A test you can do is configure an email client like Thunderbird.
Are you able to configure your domain email domain address in Thunderbird without having warning certificate?
Do you have other PHP application installed with SMTP of your domain that work?
In any case below an example on how I configured host field on my personal domain:
Now you have an example 
@SCoccia Look at your host filed, is not configured correctly.
You need specify the folder where email are (inbox)
Please consider the example sent to you and be sure to respect it.
If your domain has not been configured for have a valid certificate for email the system can be unable to send or receive emails also if you set the configuration correctly.
If you try with Gmail you will be sure the certified used by Gmail is recognized.
In my personal UVdesk install I use my domain but I have a valid certificate also for email that is not self signed.
you can try to configure your email address in an email client be sure to not add any exception if you see a warning on the certificate. If you see a warning on the certificate than you can have issues or you need ignore the certificate check.
I never remind what string you need add for ignore certificate verification.
You can search on the web. Let me see if I can find for you.
Ignore the cert verification can be a security weakness.
If I will find how and what string I will tell you.
Found, example below:
{imap.gmail.com:993/imap/ssl/novalidate-cert}INBOX
@SCoccia use an email without TLS is a security issue.
You need to know how configure email and email host.
Are you sure your host is working on the format mail.mydomain.it ?
Are you sure the port is 143?
I use port 993 with a valid certificate.
Be sure settings you insert are correct and can work in a client email for example.
There is no bugs or issue in UVdesk as I'm using this and is working so if doesn't work is probably an error in some configuration you insert. Can be the port, can be that you have no security on email (no TLS), etc.
You can try maybe with Gmail as suggested but using a specific password for app.
Usually port for outgoing email is 587 or 465
@SCoccia What I mentioned is an example.
You can replace imap.mail.yahoo.com with your domain.
I posted just an example.
Please read the guide of UVdesk I given in the previous message.
Yes, the host file is not compiled correctly.
Please see the following guide: https://www.uvdesk.com/en/blog/setup-mailbox-uvdesk-open-source-helpdesk/
Host field should be compiled for example like:
{imap.mail.yahoo.com:993/imap/ssl}INBOX
@Sanjeev I collaborated as Google volunteer contributor in the past and again I'm advising you that suggest to users to allow less secure app is like opening a security hole in users account. Maybe Google will disable this less secure app function in the future, I don't know.
@SCoccia
Google account should be always protected by the 2 step than user will need to use a specific app password as password in UVdesk settings email.
@Sanjeev new UVdesk users will continue to face installing and database issue, maybe there is no way to fix this?
I mean avoid that a new user that use a good database password with special characters will face issue of database wrong password when is not. I have to remember always to say to users that they need check their password that should not have special characters or need follow special instructions?
@Sanjeev can be the @ that create issue in database password be fixed and tested?
@SCoccia maybe your .env file has been written already.
I suggest to check if the database is empty, no table in phpmyadmin, erase UVdesk root folder and all files than recreate again the UVdesk folder with the SSH command
composer create-project uvdesk/community-skeleton helpdesk-project
than check file permission and change if necessary, point the browser to the Wizard installation and install.