Q:

SMTP Service: Do I really need it?

Since I took over this project, we have had an active subscription to CiviSMTP for all of our outgoing email in CiviCRM. We already have our email for our organization going through Gmail, but all mail through the CiviCRM is going through CiviSMTP, a service that we have to pay for. From what I understand, it's to help with anti-spam regulations and bounce rate tracking, etc. 

Can anyone offer some clarity into if this kind of service is necessary for sending out bulk emails and tracking bounce backs, etc? Is anyone else here even using it?
Can anyone recommend an SMTP service that does work with PHP 5.6 and CiviCRM 4.7.17 and allows TLS? Here is a related post to the issues I'm having with CiviSMTP: Outgoing Mail Settings, CiviSMTP & PHP 5.6.x Problem

http://www.civismtp.com/drupal/
Drupal 7.50 CiviCRM 4.7.15 PHP 5.6

A:

CiviCRM doesn't require an external mail service, it's possible to deliver mail directly from most web hosts. Quality and limitations may vary on some webhosts, and you may have to contend with other websites in a shared environment affecting your reputation.
Running your own mail service on the server/VM you run CiviCRM on is also an option but not for the faint of heart, as it requires expertise and awareness of mailing best practices. It makes sense if you have resources to dedicate, but likely requires more attention than using a reputable paid service - at least until you're sending enough mails to make a paid service expensive. If you self-host mail delivery, expect to get familiar with things like SPF, DKIM, DMARC and mail reputation.
Generally, I'd recommend checking out the hosted options available - they should take care of dependable delivery and reputation for you, and let you stick to what you do best. See:

This CiviCRM blog post on available options,
This listing of CiviCRM Mail Providers over on the wiki, 
this recent "Which mail alternatives work well?" question on CiviCRM.SE

