Sequence which works for iPad mini running iOS 13.6.1 using LTE data on a personal hotspot on the iPhone. 

1. Under Settings->Mail->Accounts. Delete the account if present. 

2. Under Settings->Profile. Select and then delete the 'Steinmetz Family CA' profile.

3. Reboot the iPad.

4. Install the profile either using AirDrop or from an email received with a different account. For the later, select the email attached certificate. Then select it again which should bring up the modal dialog about needing to go to settings to install. 

5. Under Setttings->About->Certificate Trust Settings, turn on the trust of the 'Steinmetz Family CA' certificate.

6. Under Settings->Mail->Accounts->Add Account->Other->Add Mail Account. Fill in full name, email address, password for account, and description. Next. 
Presents page titled 'New Account'. On IMAP tab, under Incoming Mail Server, fill in Host Name, User Name, Password. Under Outgoing Mail Server, fill in hostname, User Name, Password. Next.

7. 6. It now starts spinning and says "Verifying". On the server, it initiated a TLS setting but then closed it after only 90 bytes to the server and 418 back. Shortly later it initiates an smtp connection from a the proxied ip through the wireless carrier and closes it.

8. It works and saves account saved and returns to an overview of the account. 

This account is then functional. 

9. Go back to the account settings and modify the port for the outgoing mail server to the appropriate 5325. Ensure 'Use SSL' is selected and that 'Authentication' is set to 'Password'. Click Done. On the server, it initiates an smtp connection from a the proxied ip through the wireless carrier and closes it. It should now verify the account. 

This account is now functional even after switching back to a Cox account with port 25 blocked. 

Sequence attempted for iPad mini running iOS 13.6.1 using a Cox account with port 25 blocked:

1. Under Settings->Mail->Accounts. Delete the account if present. 

2. Under Setttings->About->Certificate Trust Settings, turn off the trust of the 'Steinmetz Family CA' certificate.

3. Under Settings->Profile. Select and then delete the 'Steinmetz Family CA' profile.

4. Reboot the iPad.

5. Install the profile either using AirDrop or from an email received with a different account. For the later, select the email attached certificate. Then select it again which should bring up the modal dialog about needing to go to settings to install. 

6. Under Setttings->About->Certificate Trust Settings, turn on the trust of the 'Steinmetz Family CA' certificate.

5. Under Settings->Mail->Accounts->Add Account->Other->Add Mail Account. Fill in full name, email address, password for account, and description. Next. 
Presents page titled 'New Account'. On IMAP tab, under Incoming Mail Server, fill in Host Name, User Name, Password. Under Outgoing Mail Server, fill in hostname, User Name, Password. Next.
 
6. It now starts spinning and says "Verifying". On the server, it initiated a TLS setting but then closed it after only 90 bytes to the server and 418 back. 

It spins for about 2 minutes and then times out with a modal dialog "Cannot Connect Using SSL. Do you want to try setting up the account without SSL?

7. Answer Yes to save the account. Spins "Verifying" again for about 1 minute. Then a modal dialog "The SMTP server <name> is not responding. Check your network connection and that you entered the correct information in the 'Outgoing Mail Server" field. 

8. Hit OK, then Next. Then save when it says 'This account may not be able to send or received emails. Are you sure you want to save?'. Hit Save and Save and it says 'Account Added'. 

9. Go back to the account settings and modify the port for the outgoing mail server to the appropriate 5325. Ensure 'Use SSL' is selected and that 'Authentication' is set to 'Password'. Click Done. It should now verify the account. 

This results in an account which the mail client never attempts to log in on imap to check. The details item about the error on the account in mail complains that the server is not responding.