Exchange 2013 SP1 server working for several months now messages are getting stuck in drafts folder

Question

This a small, simple environment. There is a MS Server 2012 R2 server hypervisor with a MS Server 2012 R2 VM running Exchange 2013 patched to SP1.  This server has been deployed into production and passing mail without issues for several months.
Upon initial deployment, we experienced the issue that many have reported and that has been widely documented where Mail Flow works fine inbound, but outbound will stick in the drafts folder. We resolved the issue by manually configuring the IP Address of
our internal DNS server (which is an installed role on our hypervisior / base layer server).  The issue was immediately resolved and mail was flowing in both directions without issue.  We later installed SP1 and there was no issue.  Mail has
been flowing normally all the while.
Now fast-forward through several weeks of reliable mail delivery... We experienced a power loss and a system shutdown and upon reboot, inbound is working and outbound goes to drafts.  I've confirmed DNS Lookup settings in ECP still points to our internal
server as previously configured.  Both servers have internet access, NSLOOKUP returns expected values, and DNS appears to be working normally.  
I'm not sure if we had an MS Update that installed with the reboot that caused the breakage, if there was a lingering settings change that took effect on reboot, or what is causing the interruption.  I'm looking for some fresh ideas on where to look
for answers, and all the information available on the drafts folder issue points to DNS settings that have already been put in place.  
Any constructive ideas are welcome!   Thanks in advance. 
David

Answer 1

Amit,
Long story short, I'm not sure how or why, but there were a few automatic services that were not starting "automatically."  I'm used to seeing some services that are triggered by the application to start and stop on their own, so I didn't necessarily
panic when there were a few automatic services that were stopped..
However, The MS Exchange Health Manager, and the Mailbox Submission services weren't running.  After manually starting the services my drafts folder emptied and we are back in business.. Maybe not "innovative" as you said, but it certainly put us on
the right track.  We were looking so hard at DNS because of all the reported cases of "stuck in drafts" being related to DNS, we totally overlooked the obvious, so THANKS!
Now the only question is, what stopped the services and why did they not restart automatically??