Unable to change outgoing mail (smtp) configuration / Save button is greyed out

Issue Summary

As of Jira 9.x it's not possible to update outgoing mail configuration via the UI.
Regardless of the changes to fields such as 'from' - Save button remains greyed out.
 
This is reproducible on Data Center: yes

Steps to Reproduce

1. Configure outgoing mail server, verify it works
2. Try to change server name or user name or mail from

Expected Results

Save button becomes active and allows to save the new configuration

Actual Results

Save button remains inactive & greyed out

Workaround

1. Preferred. Re-create the SMTP configuration from scratch
2. last resort. It's possible to update some of the SMTP configuration by updating the database directly (Jira restart is required) as follows:
3. Stop Jira (on all nodes if there's more than one)
4. Take a backup of the Jira database by means of native db tools (such as pg_dump for PostgreSQL)
5. Identify the mail server ID in the database, by running the following query against JIRA's database:

   select id from mailserver where server_type = 'smtp';
   

   Make a note of the ID returned.

6. update the required configuration parameter directly in the database using the ID gathered from the first step, for example, if updating 'Mail from', run the following SQL query:

   update mailserver set mailfrom = 'yourupdatedemail@yourdomain.com' where ID=<id>;
   

   Make sure to replace the <id> in the update statement, with the ID returned from step 1.

7. Start Jira and verify the change is now reflected.

For other parameters that should be possible to update via direct DB update, please reference the list below:
name
description
mailfrom
prefix
smtp_port
servername
mailusername
Notice, while there are other fields in the mailserver table, for example, protocol, server type etc, we don't recommend updating those parameters via DB update as they require more than just a direct DB update