IMAP sync error on iPhone with Letsencrypt SSL on Plesk

Issue : The issue is  the letsecrypt ssl was generated for domain.com but the configuration was made in mail.domain.com which was showing as untrusted in iphone

Solution:

1. Launch the Settings app from your Home screen

2. Now scroll down and tap on Mails, Contacts and Calendars

3. Then tap on Add Account

4. Add new account

5. Now select your account type. Please tap other if your account is not listed

6. Enter the new account information

In the certificate options go to more details:

Enter the incoming and outgoing hostnames matched with the certificate that is given to domain name and put the correct validity period of the SSL certificate.

Note: In this, the certificate is given to domain.com so the incoming and outgoing hostnames will be domain.com instead of mail.domain.com

Then the error popup will be shown and click on the OK button

Put the correct incoming server details that are hostname and username

In the outgoing server details, click on the advanced options

Put the correct hostname, username and enable the SSL option, and put the port 587

Now the configuration is done on the iPhone

Changes in Plesk settings for TLS versions in Plesk.

Login into the Plesk panel

Go to the SSL/TLS options and make the changes

In the additional components to secure option  in that there is server configuration option enable the TLS versions and ciphers by Mozilla

Now the TLS version is successfully enabled to the domain