Hi-Bye Vs Dear-Near
It is a debated salutation in email. We have the habit of always using the salutation of 'Hi' in our emails. The word 'Hi' is too very formal and sometimes in spiritual terms also offers to spread a bit of negative waves. Phonetically you can observe that 'Hi' sounds similar to 'Bye' (which means bidding adieu). On the other hand, a salutation with 'Dear' brings people closer ('nearer').
Let us say a 'Hi' to hi and bid adieu ('bye') to it and say 'Hello' to 'Dear' making people to come nearer and closer.