Q: 9.3.4 Update - Microsoft Exchange Won't Synch

Hi glmcauley,

Thanks for checking out the Apple Support Communities. I understand you're having trouble with adding an Exchange email account on to your iPhone after updating. It's important to have access to the info in that account when you need it and I'm happy to offer some suggestions to help you. 

The first thing that I'd like to make sure of is that you've followed the steps listed in this article to try and set up your Exchange account:

Set up Exchange ActiveSync on your iPhone, iPad, or iPod touch

You can also take a look at the troubleshooting steps listed in the article below. If everything here checks out, it's possible that an update may need to be done on your IT Department's end. 

Get help with Mail on your iPhone, iPad, and iPod touch

If neither of these articles offer any resolution, the next recommendation would be to backup your iPhone, then restore it using iTunes. Once it's restored, you'll want to set it up as a new device (temporarily) and test it out by trying to add the account on. This will help narrow down if there's an issue with the software that was installed or with a file in your backup. Once you test it out, if everything's working ok, you can try restoring the backup and testing it out again. You can find everything you'll need to do this in the articles below. 

How to back up your iPhone, iPad, and iPod touch

Use iTunes on your Mac or PC to restore your iPhone, iPad, or iPod to factory settings

Restore your iPhone, iPad, or iPod touch from a backup

Cheers!