Hello CK,
Yep, that's right. Cronjob not only solves issues with timeouts but if you are going to enable sending e-mails on page load, your users is going to find the site to load very slow. Imagine the workflow below:
1. User's post a comment
2. EasySocial sends e-mail
-- This onwards will run as many times as it needs to. If you have 100 e-mails, it processes 100 times
3. Joomla's mailer api creates a connection to the SMTP server
4. Waits for the result from the SMTP server
----
5. Done