Is it possible to redirect a subdomain that I've created to a specific folder, without touch apache config files? Only using Digital Ocean's DNS admin?

No, that is not possible. You will need to create a virtualhost and configure it to redirect to http://panel.mydomain.com/etc/apps/webmail/.

I am sure there is a guide somewhere on this site that is helpful to a point, but they're vague. No problem there, trying to make them accessible and malleable, but on another page regarding subdomains, Kamal said, "Make sure that DNS is properly setup and restart Apache and you should be good to go."

Now, I understand copying the domain.com file to sub.domain.com in sites-available, then running sudo a2ensite sub.domain.com and then restarting apache.

But as far as the DNS goes...give it to me straight. Do I:
1. Create a new domain record set under DNS in the control panel that is sub.domain.com, with an A record of @ , xx.xx.xx.xx ? Or,
2. In the already existing DNS record for domain.com, simply add another A record of sub.domain.com , xx.xx.xx.xx? Or,
3. Is there another way of doing this?

The site is enabled, but I'm not sure "how to setup the DNS properly".

Thanks very much in advance!

Now, I understand copying the domain.com file to sub.domain.com in sites-available, then running sudo a2ensite sub.domain.com and then restarting apache.
Make sure you edit it and replace all occurrences of domain.com with sub.domain.com as well.

The easiest way would be creating an A record for 'sub' pointing to your droplet's IP on the existing DNS zone for domain.com.

WOOT! Thank you!!

Hello people,

Quick question. Is it possible to redirect a subdomain that I've created to a specific folder, without touch apache config files? Only using Digital Ocean's DNS admin?
Example:

redirect email.mydomain.com ( redirects to http://panel.mydomain.com/etc/apps/webmail/ )