From 'I'm sending this follow-up letter to let you know that your support is greatly needed and appreciated by everyone involved with graduate Endodontics at IU.', can we conclude that 'I have sent you 50 letters before this follow-up letter because you refuse to answer any other letters.' is unrelated and maintains neutrality?
I'm sending this follow-up letter to let you know that your support is greatly needed and appreciated by everyone involved with graduate Endodontics at IU.###I have sent you 50 letters before this follow-up letter because you refuse to answer any other letters.