Evernote instituted per-account rate limits for their synchronization server in November of 2013. If you sync a great deal of notes with a lot of resources, you may hit the rate limit error. Evernote has given us a feature called "Initial Sync Booster" which is setup on Evernote's side and is turned on as of April 17th 2014. The Initial Sync Booster provides an extremely high rate limit for 24 hours after Pocket Informant is given access to your Evernote account.
For new users this process should be automatic: Create an Evernote Sync account, sign in and give Pocket Informant permission, and then sync within 24 hours.
For users performing a reset sync at a future date you must follow the steps below:
Login to the Evernote website and click on your name in the top right->Account Settings.
Go to Applications.
Revoke permissions to Pocket Informant
Open Pocket Informant and open the Evernote sync account