They are two different protocols. Post Office Protocol, which works like a post office box, where you go to get your mail, and Internet Message Access Protocol, which works by synchronising with the server. In most cases, I recommend IMAP. These pages may help you decide:
Sure, some fresh injuries might hurt for a short time frame. However, unless there is a definitive neurological link, these will heal and the pain should stop. If not, then there is a good chance that the pain is not due to the herniated disc at all. So, some herniations can heal, some may not. Degeneration never heals. However, statistics show that healing is not needed in order for the back or neck symptoms to resolve.
Exercises that strengthen the core muscles of the upper body can help to relieve pain and the effects of a ruptured disc. Medication is used to relieve the pain but it doesn't treat the cause of the pain so you should try not to simply rely on medication for controlling your sciatica.